ADVERSE REACTIONS SECTION.

6 ADVERSE REACTIONS. The following serious adverse reactions are described elsewhere in the labeling:Hypotension, bradycardia, and syncope [see Warnings and Precautions 5.1 )] Sedation and somnolence [see Warnings and Precautions 5.2 )] Cardiac conduction abnormalities [see Warnings and Precautions 5.3 )] Rebound Hypertension [see Warnings and Precautions (5.4)] Hypotension, bradycardia, and syncope [see Warnings and Precautions 5.1 )] Sedation and somnolence [see Warnings and Precautions 5.2 )] Cardiac conduction abnormalities [see Warnings and Precautions 5.3 )] Rebound Hypertension [see Warnings and Precautions (5.4)] Most common adverse reactions (greater than or equal to 5% and at least twice placebo rate) in fixed-dose monotherapy ADHD trials in children and adolescents (6 to 17 years): hypotension, somnolence, fatigue, nausea, and lethargy 6.1) Flexible dose-optimization ADHD trials in children (6 to 12 years): somnolence, hypotension, abdominal pain, insomnia, fatigue, dizziness, dry mouth, irritability, nausea, vomiting, and bradycardia 6.1). Adjunctive treatment to psychostimulant ADHD trial in children and adolescents (6 to 17 years): somnolence, fatigue, insomnia, dizziness, and abdominal pain 6.1). To report SUSPECTED ADVERSE REACTIONS, contact AvKARE, Inc. at 1-855-361-3993 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience. Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.The data described below reflect clinical trial exposure to guanfacine extended-release in 2,028 patients. This includes 1,533 patients from completed studies in children and adolescents, ages to 17 years and 495 patients in completed studies in adult healthy volunteers.The mean duration of exposure of 446 patients that previously participated in two 2-year, open-label long-term studies was approximately 10 months.Fixed Dose TrialsTable 3: Percentage of Patients Experiencing Most Common (>=5% and at least twice the rate for placebo) Adverse Reactions in Fixed Dose Studies and G uanfacine xtended- elease (mg) Adverse Reaction Term Placebo (N=149) mg (N=61) mg (N=150) mg (N=151) mg (N=151) All Doses of uanfacine xtended- elease (N=513) Somnolence 11% 28% 30% 38% 51% 38% Fatigue 3% 10% 13% 17% 15% 14% Hypotension 3% 8% 5% 7% 8% 7% Dizziness 4% 5% 3% 7% 10% 6% Lethargy 3% 2% 3% 8% 7% 6% Nausea 2% 7% 5% 5% 6% 6% Dry mouth 1% 0% 1% 6% 7% 4% The lowest dose of mg used in Study was not randomized to patients weighing more than 50 kg. aThe somnolence term includes somnolence, sedation, and hypersomnia. bThe hypotension term includes hypotension, diastolic hypotension, orthostatic hypotension, blood pressure decreased, blood pressure diastolic decreased, blood pressure systolic decreased). Table 4: Adverse Reactions Leading to Discontinuation (>=2% for all doses of Guanfacine Extended-Release and rate in placebo) in Fixed Dose Studies and G uanfacine xtended- elease (mg) Adverse Reaction Term Placebo (N=149) mg (N=61) mg (N=150) mg (N=151) mg (N=151) All Doses of uanfacine xtended- elease (N=513) (%) (%) (%) (%) (%) (%) Total patients (3%) (3%) 10 (7%) 15 (10%) 27 (18%) 54 (11%) Somnolence 1 (1%) (3%) (3%) (4%) 17 (11%) 30 (6%) Fatigue (0%) (0%) (1%) (1%) (3%) (2%) Adverse reactions leading to discontinuation in >= 2% in any dose group but did not meet this criteria in all doses combined: hypotension (hypotension, diastolic hypotension, orthostatic hypotension, blood pressure decreased, blood pressure diastolic decreased, blood pressure systolic decreased), headache, and dizziness. The lowest dose of mg used in Study was not randomized to patients weighing more than 50 kg. aThe somnolence term includes somnolence, sedation, and hypersomnia. Table 5: Other Common Adverse Reactions (>=2%for all doses of Guanfacine Extended-Release and rate than in placebo) in Fixed Dose Studies and G uanfacine xtended- elease (mg) Adverse Reaction Term Placebo (N=149) mg (N=61) mg (N=150) mg (N=151) mg (N=151) All Doses of uanfacine xtended- elease (N=513) Headache 19% 26% 25% 16% 28% 23% Abdominal Pain 9% 10% 7% 11% 15% 11% Decreased Appetite 4% 5% 4% 9% 6% 6% Irritability 4% 5% 8% 3% 7% 6% Constipation 1% 2% 2% 3% 4% 3% Nightmare 0% 0% 0% 3% 4% 2% Enuresis 1% 0% 1% 3% 2% 2% Affect Lability 1% 2% 1% 3% 1% 2% Adverse reactions >= 2% for all doses of guanfacine extended-release and rate in placebo in any dose group but did not meet this criteria in all doses combined: insomnia (insomnia, initial insomnia, middle insomnia, terminal insomnia, sleep disorder), vomiting, diarrhea, abdominal/stomach discomfort (abdominal discomfort, epigastric discomfort, stomach discomfort), rash (rash, rash generalized, rash papular), dyspepsia, increased weight, bradycardia (bradycardia, sinus bradycardia), asthma (asthma, bronchospasm, wheezing), agitation, anxiety (anxiety, nervousness), sinus arrhythmia, blood pressure increased (blood pressure increased, blood pressure diastolic increased), and first degree atrioventricular block. The lowest dose of mg used in Study was not randomized to patients weighing more than 50 kg. aThe abdominal pain term includes abdominal pain, abdominal pain lower, abdominal pain upper, and abdominal tenderness. bThe nightmare term includes abnormal dreams, nightmare, and sleep terror. cThe enuresis term includes enuresis, nocturia, and urinary incontinence. dThe affect lability term includes affect lability and mood swings. Monotherapy Flexible Dose TrialsTable 6: Percentage of Patients Experiencing Most Common (>=5% and at least twice the rate for placebo) Adverse Reactions in the Monotherapy Flexible Dose Study G uanfacine xtended- elease Adverse Reaction Term Placebo (N=112) AM (N=107) PM (N=114) All Doses of uanfacine xtended- elease (N =221) Somnolence 15% 57% 54% 56% Abdominal Pain 7% 8% 19% 14% Fatigue 3% 10% 11% 11% Irritability 3% 7% 7% 7% Nausea 1% 6% 5% 5% Dizziness 3% 6% 4% 5% Vomiting 2% 7% 4% 5% Hypotension 0% 6% 4% 5% Decreased Appetite 3% 6% 3% 4% Enuresis 1% 2% 5% 4% aThe somnolence term includes somnolence, sedation, and hypersomnia. bThe abdominal pain term includes abdominal pain, abdominal pain lower, abdominal pain upper, and abdominal tenderness cThe hypotension term includes hypotension, diastolic hypotension, orthostatic hypotension, blood pressure decreased, blood pressure diastolic decreased, blood pressure systolic decreased). dThe enuresis term includes enuresis, nocturia, and urinary incontinence. Table 7: Adverse Reactions Leading to Discontinuation (>=2% for all doses of Guanfacine Extended-Release and rate than in placebo) in Monotherapy Flexible Dose Study G uanfacine xtended- elease Adverse Reaction Term Placebo (N=112) AM (N=107) PM (N=114) All Doses of uanfacine xtended- elease (N=221) (%) (%) (%) (%) Total patients (0%) (7%) (6%) 15 (7%) Somnolence 0 (0%) (4%) (3%) (3%) Adverse reactions leading to discontinuation in greater than or equal to 2% in any dose group bud did not meet this criteria in all doses combined: fatigue aThe somnolence term includes somnolence, sedation, and hypersomnia. Table 8: Other Common Adverse Reactions (>=2% for all doses of Guanfacine Extended-Release and rate than in placebo) in the Monotherapy Flexible Dose Study G uanfacine xtended- elease Adverse Reaction Term Placebo (N=112) AM (N=107) PM (N=114) All Doses of uanfacine xtended- elease (N=221) Headache 11% 18% 16% 17% Insomnia 6% 8% 6% 7% Diarrhea 4% 4% 6% 5% Lethargy 0% 4% 3% 3% Constipation 2% 2% 4% 3% Dry Mouth 1% 3% 3% 3% Adverse reactions >= 2% for all doses of guanfacine extended-release and rate in placebo in any dose group but did not meet this criteria in all doses combined: affect lability (affect lability, mood swings), increased weight, syncope/loss of consciousness (loss of consciousness, presyncope, syncope), dyspepsia, tachycardia (tachycardia, sinus tachycardia), and bradycardia (bradycardia, sinus bradycardia). aThe insomnia term includes insomnia, initial insomnia, middle insomnia, terminal insomnia, and sleep disorder. Adjunctive TrialTable 11: Percentage of Patients Experiencing Most Common (>=5% and at least twice the rate for placebo) Adverse Reactions in the Short-Term Adjunctive Study G uanfacine xtended- elease stimulant Adverse Reaction Term Placebo+ stimulant (N=153) AM (N=150) PM (N=152) All Doses (N=302) Somnolence 7% 18% 18% 18% Insomnia 6% 10% 14% 12% Abdominal Pain 3% 8% 12% 10% Fatigue 3% 12% 7% 10% Dizziness 4% 10% 5% 8% Decreased Appetite 4% 7% 8% 7% Nausea 3% 3% 7% 5% aThe somnolence term includes somnolence, sedation, and hypersomnia. bThe insomnia term includes insomnia, initial insomnia, middle insomnia, terminal insomnia, and sleep disorder. cThe abdominal pain term includes abdominal pain, abdominal pain lower, abdominal pain upper, and abdominal tenderness. There were no specific adverse reactions greater than or equal to 2% in any treatment group that led to discontinuation in the short-term adjunctive study (Study 3).Table 12: Other Common Adverse Reactions (>=2% for all doses of Guanfacine Extended-Release and rate than in placebo) in the Short-Term Adjunctive Study G uanfacine xtended- elease stimulant Adverse Reaction Term Placebo (N=153) AM (N=150) PM (N=152) All Doses of uanfacine xtended- elease (N=302) Headache 13% 21% 21% 21% Diarrhea 1% 4% 3% 4% Hypotension 0% 4% 2% 3% Constipation 0% 2% 3% 2% Affect Lability 1% 3% 2% 2% Dry Mouth 0% 1% 3% 2% Bradycardia 0% 1% 3% 2% Postural Dizziness 0% 1% 3% 2% Rash 1% 1% 2% 2% Nightmare 1% 2% 1% 2% Tachycardia 1% 2% 1% 2% Adverse reactions greater than or equal to 2% for all doses of guanfacine extended-release and greater than rate in placebo in any dose group but did not meet this criteria in all doses combined: irritability, vomiting, asthma (asthma, bronchospasm, wheezing), and enuresis (enuresis, nocturia, urinary incontinence). aThe hypotension term includes hypotension, diastolic hypotension, orthostatic hypotension, blood pressure decreased, blood pressure diastolic decreased, blood pressure systolic decreased. bThe affect lability term includes affect lability and mood swings. cThe bradycardia term includes bradycardia and sinus bradycardia. dThe rash term includes rash, rash generalized, and rash papular. eThe nightmare term includes abnormal dreams, nightmare, and sleep terror. fThe tachycardia term includes tachycardia and sinus tachycardia. Effects on Blood Pressure and Heart RateIn the monotherapy pediatric, short-term, controlled trials (Studies and 2), the maximum mean changes from baseline in seated systolic blood pressure, diastolic blood pressure, and pulse were -5.4 mmHg, -3.4 mmHg, and -5.5 bpm, respectively, for all doses combined (generally one week after reaching target doses). For the respective fixed doses mg/day, mg/day, mg/day or mg/day the maximum mean changes in seated systolic blood pressure were -4.3 mmHg, -5.5 mmHg, -5.4 mmHg and -8.2 mmHg. For these respective fixed doses the maximum mean changes in seated diastolic blood pressure were -3.4 mmHg, -3.3 mmHg, -4.4 mmHg and -5.4 mmHg. For these respective fixed doses the maximum mean changes in seated pulse were -4.8 bpm, -3.1 bpm, -6.5 bpm and -8.6 bpm. Decreases in blood pressure and heart rate were usually modest and asymptomatic; however, hypotension and bradycardia can occur. Hypotension was reported as an adverse reaction for 7% of the guanfacine extended-release group and 3% of the placebo group. This includes orthostatic hypotension, which was reported for 1% of the guanfacine extended-release group and none in the placebo group. These findings were generally similar in the monotherapy flexible dose trial (Study 4). In the adjunctive trial, hypotension (3%) and bradycardia (2%) were observed in patients treated with guanfacine extended-release as compared to none in the placebo group. In long-term, open-label studies, (mean exposure of approximately 10 months), maximum decreases in systolic and diastolic blood pressure occurred in the first month of therapy. Decreases were less pronounced over time. Syncope occurred in 1% of pediatric patients in the clinical program. The majority of these cases occurred in the long-term, open-label studies.Effects on Height, Weight, and Body Mass Index (BMI)Patients taking guanfacine extended-release demonstrated similar growth compared to normative data. Patients taking guanfacine extended-release had mean increase in weight of 0.5 kg compared to those receiving placebo over comparable treatment period. Patients receiving guanfacine extended-release for at least 12 months in open-label studies gained an average of kg in weight and cm (3 in) in height. The height, weight, and BMI percentile remained stable in patients at 12 months in the long-term studies compared to when they began receiving guanfacine extended-release.Other Adverse Reactions Observed in Clinical StudiesTable 13 includes additional adverse reactions observed in short-term, placebo-controlled and long-term, open-label clinical studies not included elsewhere in section 6.1, listed by organ system.Table 13: Other Adverse Reactions Observed in Clinical Studies Body System Adverse Reaction Cardiac Atrioventricular block General Asthenia, chest pain Immune System Disorders Hypersensitivity Investigations Increased alanine amino transferase Nervous system Convulsion Renal Increased urinary frequency Vascular Hypertension, pallorAdditional pediatric use information for patients ages to 17 years is approved for Shire US Inc.s INTUNIV(R) (guanfacine) extended-release tablet product. However, due to Shire US Inc.s marketing exclusivity rights, this drug product is not labeled with that pediatric information.. 6.2 Postmarketing Experience. The following adverse reactions have been identified during post-approval use of guanfacine. Because these reactions are reported voluntarily from population of uncertain size, it is not always possible to reliably estimate their frequency or establish causal relationship to drug exposure.Less frequent, possibly guanfacine-related events observed in the postmarketing study and/or reported spontaneously, not included in section 6.1, include:General: edema, malaise, tremor Cardiovascular: palpitations, tachycardia, rebound hypertension, hypertensive encephalopathy Central Nervous System: paresthesias, vertigo Eye Disorders: blurred vision Musculo keletal System: arthralgia, leg cramps, leg pain, myalgia Psychiatric: confusion, hallucinations Reproductive System, Male: impotence Respiratory System: dyspnea Skin and Appendages: alopecia, dermatitis, exfoliative dermatitis, pruritus, rash Special Senses: alterations in taste.

USE IN SPECIFIC POPULATIONS SECTION.

8 USE IN SPECIFIC POPULATIONS. 8.1 Pregnancy. Pregnancy Category BRisk SummaryThere are no adequate and well-controlled studies of guanfacine extended-release in pregnant women. No fetal harm was observed in rats and rabbits with administration of guanfacine at and 2.7 times, respectively, the maximum recommended human dose. Because animal studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.Animal dataReproduction studies conducted in rats have shown that guanfacine crosses the placenta. However, administration of guanfacine to rats and rabbits at and 2.7 times, respectively, the maximum recommended human dose of 0.12 mg/kg/day on mg/m basis resulted in no evidence of harm to the fetus. Higher doses (13.5 times the maximum recommended human dose in both rabbits and rats) were associated with reduced fetal survival and maternal toxicity. 8.3 Nursing Mothers. It is not known whether guanfacine is excreted in human milk; however, guanfacine is excreted in rat milk. Because many drugs are excreted in human milk, caution should be exercised when guanfacine extended-release is administered to nursing woman. Observe human milk-fed infants for sedation and somnolence.. 8.4 Pediatric Use. Safety and efficacy of guanfacine extended-release in pediatric patients less than years of age have not been established. The efficacy of guanfacine extended-release was studied for the treatment of ADHD in three controlled monotherapy clinical trials (up to weeks in duration), and one controlled adjunctive trial with psychostimulants (8 weeks in duration) in children and adolescents ages to 17 who met DSM-IV (R) criteria for ADHD [see Adverse Reactions 6 and Clinical Studies 14 )]. Additional pediatric use information for patients ages to 17 years is approved for Shire US Inc.s INTUNIV(R) (guanfacine) extended-release tablet product. However, due to Shire US Inc.s marketing exclusivity rights, this drug product is not labeled with that pediatric information.Animal DataIn studies in juvenile rats, guanfacine alone produced slight delay in sexual maturation in males and females at to times the maximum recommended human dose (MRHD). Guanfacine in combination with methylphenidate produced slight delay in sexual maturation and decreased growth as measured by decrease in bone length in males at dose of guanfacine comparable to the MRHD and dose of methylphenidate approximately times the MRHD.In study where juvenile rats were treated with guanfacine alone from to 59 days of age, development was delayed as indicated by slight delay in sexual maturation and decreased body weight gain in males at mg/kg/day and in females at mg/kg/day. The No Adverse Effect Level (NOAEL) for delayed sexual maturation was mg/kg/day, which is equivalent to the MRHD of mg/day, on mg/m basis. The effects on fertility were not evaluated in this study. In study where juvenile rats were treated with guanfacine in combination with methylphenidate from to 59 days of age, decrease in ulna bone length and slight delay in sexual maturation were observed in males given mg/kg/day of guanfacine in combination with 50 mg/kg/day of methylphenidate. The NOAELs for these findings were 0.3 mg/kg of guanfacine in combination with 16 mg/kg/day of methylphenidate, which are equivalent to 0.3 and 1.4 times the MRHD of mg/day and 54 mg/day for guanfacine and methylphenidate, respectively, on mg/m basis. These findings were not observed with guanfacine alone at mg/kg/day or methylphenidate alone at 50 mg/kg/day. 8.5 Geriatric Use. The safety and efficacy of guanfacine extended-release in geriatric patients have not been established.. 8.6 Renal Impairment. It may be necessary to reduce the dosage in patients with significant impairment of renal function [see Clinical Pharmacology 12.3 )]. 8.7 Hepatic Impairment. It may be necessary to reduce the dosage in patients with significant impairment of hepatic function [see Clinical Pharmacology 12.3 )].

WARNINGS AND PRECAUTIONS SECTION.

5 WARNINGS AND PRECAUTIONS. Hypotension, bradycardia, syncope: Titrate slowly and monitor vital signs frequently in patients at risk for hypotension, heart block, bradycardia, syncope, cardiovascular disease, vascular disease, cerebrovascular disease or chronic renal failure. Measure heart rate and blood pressure prior to initiation of therapy, following dose increases, and periodically while on therapy. Avoid concomitant use of drugs with additive effects unless clinically indicated. Advise patients to avoid becoming dehydrated or overheated 5.1). Sedation and somnolence: Occur commonly with guanfacine extended-release. Consider the potential for additive sedative effects with CNS depressant drugs. Caution patients against operating heavy equipment or driving until they know how they respond to guanfacine extended-release 5.2). Cardiac Conduction Abnormalities: May worsen sinus node dysfunction and atrioventricular (AV) block, especially in patients taking other sympatholytic drugs. Titrate slowly and monitor vital signs frequently 5.3). Rebound Hypertension: Abrupt discontinuation of guanfacine extended-release tablets can lead to clinically significant and persistent rebound hypertension. Subsequent hypertensive encephalopathy was also reported. To minimize the risk of rebound hypertension upon discontinuation, the total daily dose of guanfacine extended-release tablets should be tapered in decrements of no more than mg every to days 5.4). Hypotension, bradycardia, syncope: Titrate slowly and monitor vital signs frequently in patients at risk for hypotension, heart block, bradycardia, syncope, cardiovascular disease, vascular disease, cerebrovascular disease or chronic renal failure. Measure heart rate and blood pressure prior to initiation of therapy, following dose increases, and periodically while on therapy. Avoid concomitant use of drugs with additive effects unless clinically indicated. Advise patients to avoid becoming dehydrated or overheated 5.1). Sedation and somnolence: Occur commonly with guanfacine extended-release. Consider the potential for additive sedative effects with CNS depressant drugs. Caution patients against operating heavy equipment or driving until they know how they respond to guanfacine extended-release 5.2). Cardiac Conduction Abnormalities: May worsen sinus node dysfunction and atrioventricular (AV) block, especially in patients taking other sympatholytic drugs. Titrate slowly and monitor vital signs frequently 5.3). Rebound Hypertension: Abrupt discontinuation of guanfacine extended-release tablets can lead to clinically significant and persistent rebound hypertension. Subsequent hypertensive encephalopathy was also reported. To minimize the risk of rebound hypertension upon discontinuation, the total daily dose of guanfacine extended-release tablets should be tapered in decrements of no more than mg every to days 5.4). 5.1 Hypotension, Bradycardia, and Syncope. Treatment with guanfacine extended-release can cause dose-dependent decreases in blood pressure and heart rate. Decreases were less pronounced over time of treatment. Orthostatic hypotension and syncope have been reported [see Adverse Reactions 6.1 )]. Measure heart rate and blood pressure prior to initiation of therapy, following dose increases, and periodically while on therapy. Titrate guanfacine extended-release slowly in patients with history of hypotension, and those with underlying conditions that may be worsened by hypotension and bradycardia; e.g., heart block, bradycardia, cardiovascular disease, vascular disease, cerebrovascular disease, or chronic renal failure. In patients who have history of syncope or may have condition that predisposes them to syncope, such as hypotension, orthostatic hypotension, bradycardia, or dehydration, advise patients to avoid becoming dehydrated or overheated. Monitor blood pressure and heart rate, and adjust dosages accordingly in patients treated concomitantly with antihypertensives or other drugs that can reduce blood pressure or heart rate or increase the risk of syncope.. 5.2 Sedation and Somnolence. Somnolence and sedation were commonly reported adverse reactions in clinical studies [see Adverse Reactions 6.1 )]. Before using guanfacine extended-release with other centrally active depressants, consider the potential for additive sedative effects. Caution patients against operating heavy equipment or driving until they know how they respond to treatment with guanfacine extended-release. Advise patients to avoid use with alcohol. 5.3 Cardiac Conduction Abnormalities. The sympatholytic action of guanfacine extended-release may worsen sinus node dysfunction and atrioventricular (AV) block, especially in patients taking other sympatholytic drugs. Titrate guanfacine extended-release slowly and monitor vital signs frequently in patients with cardiac conduction abnormalities or patients concomitantly treated with other sympatholytic drugs.. 5.4 Rebound Hypertension. In post marketing experience, abrupt discontinuation of guanfacine extended-release tablets has resulted in clinically significant and persistent rebound hypertension above baseline levels and increases in heart rate. Hypertensive encephalopathy has also been reported in association with rebound hypertension with both guanfacine extended-release tablets and immediate release guanfacine [see Adverse Reactions 6.2 )]. In these cases, high-dosage guanfacine was discontinued; concomitant stimulant use was also reported, which may potentially increase hypertensive response upon abrupt discontinuation of guanfacine. Children commonly have gastrointestinal illnesses that lead to vomiting, and resulting inability to take medications, so they may be especially at risk for rebound hypertension. To minimize the risk of rebound hypertension upon discontinuation, the total daily dose of guanfacine extended-release tablets should be tapered in decrements of no more than mg every to days [see Dosage and Administration 2.5 )]. Blood pressure and heart rate should be monitored when reducing the dose or discontinuing guanfacine extended-release tablets. If abrupt discontinuation occurs (especially with concomitant stimulant use), patients should be closely followed for rebound hypertension.

CLINICAL PHARMACOLOGY SECTION.

12 CLINICAL PHARMACOLOGY. 12.1 Mechanism of Action. Guanfacine is central alpha 2A-adrenergic receptor agonist. Guanfacine is not central nervous system (CNS) stimulant. The mechanism of action of guanfacine in ADHD is not known. 12.2 Pharmacodynamics. Guanfacine is selective central alpha 2A-adrenergic receptor agonist in that it has 15 to 20 times higher affinity for this receptor subtype than for the alpha 2B or alpha 2C subtypes. Guanfacine is known antihypertensive agent. By stimulating central alpha 2A-adrenergic receptors, guanfacine reduces sympathetic nerve impulses from the vasomotor center to the heart and blood vessels. This results in decrease in peripheral vascular resistance and reduction in heart rate. In thorough QT study, the administration of two dose levels of immediate-release guanfacine (4 mg and mg) produced concentrations approximately to times the concentrations observed with the maximum recommended dose of guanfacine extended-release of 0.12 mg/kg. Guanfacine was not shown to prolong the QTc interval to any clinically relevant extent.. 12.3 Pharmacokinetics. Absorption and DistributionGuanfacine is readily absorbed and approximately 70% bound to plasma proteins independent of drug concentration. After oral administration of guanfacine extended-release the time to peak plasma concentration is approximately hours in children and adolescents with ADHD.Immediate-release guanfacine and guanfacine extended-release have different pharmacokinetic characteristics; dose substitution on milligram per milligram basis will result in differences in exposure.A comparison across studies suggests that the max is 60% lower and AUC 0- 43% lower, respectively, for guanfacine extended-release compared to immediate-release guanfacine. Therefore, the relative bioavailability of guanfacine extended-release to immediate-release guanfacine is 58%. The mean pharmacokinetic parameters in adults following the administration of guanfacine extended-release mg once daily and immediate-release guanfacine mg once daily are summarized in Table 15. Table 15: Comparison of Pharmacokinetics: Guanfacine Extended-Release vs. Immediate release Guanfacine in Adults Parameter uanfacine xtended- elease mg once daily (n=52) Immediate- elease uanfacine mg once daily (n=12) max (ng/mL) 1.0 +- 0.3 2.5 +- 0.6 AUC 0- (ng.h/mL) 32 +- 56 +- 15 max (h) 6.0 (4.0 8.0) 3.0 (1.5-4.0) 1/2 (h) 18 +- 16 +- 3Note: Values are mean +/- SD, except for max which is median (range) Figure 1: Comparison of Pharmacokinetics: Guanfacine Extended-Release vs. Immediate-release Guanfacine in Adults Exposure to guanfacine was higher in children (ages to 12) compared to adolescents (ages 13 to 17) and adults. After oral administration of multiple doses of guanfacine extended-release mg, the max was 10 ng/mL compared to ng/mL and the AUC was 162 ngoh/mL compared to 116 ngoh/mL in children (ages to 12) and adolescents (ages 13 to 17), respectively. These differences are probably attributable to the lower body weight of children compared to adolescents and adults. The pharmacokinetics were affected by intake of food when single dose of guanfacine extended-release mg was administered with high-fat breakfast. The mean exposure increased (C max ~75% and AUC ~40%) compared to dosing in fasted state. Dose ProportionalityFollowing administration of guanfacine extended-release in single doses of mg, mg, mg, and mg to adults, max and AUC 0- of guanfacine were proportional to dose. Metabolism and EliminationIn vitro studies with human liver microsomes and recombinant CYPs demonstrated that guanfacine was primarily metabolized by CYP3A4. In pooled human hepatic microsomes, guanfacine did not inhibit the activities of the major cytochrome P450 isoenzymes (CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6 or CYP3A4/5). Guanfacine is substrate of CYP3A4/5 and exposure is affected by CYP3A4/5 inducers/inhibitors. Studies in Specific PopulationsRenal ImpairmentThe impact of renal impairment on the pharmacokinetics of guanfacine in children was not assessed. In adult patients with impaired renal function, the cumulative urinary excretion of guanfacine and the renal clearance diminished as renal function decreased. In patients on hemodialysis, the dialysis clearance was about 15% of the total clearance. The low dialysis clearance suggests that the hepatic elimination (metabolism) increases as renal function decreases.Hepatic ImpairmentThe impact of hepatic impairment on PK of guanfacine in children was not assessed. Guanfacine in adults is cleared both by the liver and the kidney, and approximately 50% of the clearance of guanfacine is hepatic [see Hepatic Impairment 8.7 )]. Drug Interaction StudiesGuanfacine is primarily metabolized by CYP3A4 and its plasma concentrations can be affected significantly by CYP3A4 inhibitors or inducers (Figure 2).Guanfacine does not significantly affect exposures of methylphenidate and lisdexamfetamine when coadministered (Figure 3).. correct-figure. Figure 2: Effect of Other Drugs on the Pharmacokinetics (PK) of Guanfacine Extended-Release. Figure 3: Effect of Guanfacine Extended-Release on the Pharmacokinetics (PK) of Other Drugs.

CLINICAL STUDIES SECTION.

6.1 Clinical Trials Experience. Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.The data described below reflect clinical trial exposure to guanfacine extended-release in 2,028 patients. This includes 1,533 patients from completed studies in children and adolescents, ages to 17 years and 495 patients in completed studies in adult healthy volunteers.The mean duration of exposure of 446 patients that previously participated in two 2-year, open-label long-term studies was approximately 10 months.Fixed Dose TrialsTable 3: Percentage of Patients Experiencing Most Common (>=5% and at least twice the rate for placebo) Adverse Reactions in Fixed Dose Studies and G uanfacine xtended- elease (mg) Adverse Reaction Term Placebo (N=149) mg (N=61) mg (N=150) mg (N=151) mg (N=151) All Doses of uanfacine xtended- elease (N=513) Somnolence 11% 28% 30% 38% 51% 38% Fatigue 3% 10% 13% 17% 15% 14% Hypotension 3% 8% 5% 7% 8% 7% Dizziness 4% 5% 3% 7% 10% 6% Lethargy 3% 2% 3% 8% 7% 6% Nausea 2% 7% 5% 5% 6% 6% Dry mouth 1% 0% 1% 6% 7% 4% The lowest dose of mg used in Study was not randomized to patients weighing more than 50 kg. aThe somnolence term includes somnolence, sedation, and hypersomnia. bThe hypotension term includes hypotension, diastolic hypotension, orthostatic hypotension, blood pressure decreased, blood pressure diastolic decreased, blood pressure systolic decreased). Table 4: Adverse Reactions Leading to Discontinuation (>=2% for all doses of Guanfacine Extended-Release and rate in placebo) in Fixed Dose Studies and G uanfacine xtended- elease (mg) Adverse Reaction Term Placebo (N=149) mg (N=61) mg (N=150) mg (N=151) mg (N=151) All Doses of uanfacine xtended- elease (N=513) (%) (%) (%) (%) (%) (%) Total patients (3%) (3%) 10 (7%) 15 (10%) 27 (18%) 54 (11%) Somnolence 1 (1%) (3%) (3%) (4%) 17 (11%) 30 (6%) Fatigue (0%) (0%) (1%) (1%) (3%) (2%) Adverse reactions leading to discontinuation in >= 2% in any dose group but did not meet this criteria in all doses combined: hypotension (hypotension, diastolic hypotension, orthostatic hypotension, blood pressure decreased, blood pressure diastolic decreased, blood pressure systolic decreased), headache, and dizziness. The lowest dose of mg used in Study was not randomized to patients weighing more than 50 kg. aThe somnolence term includes somnolence, sedation, and hypersomnia. Table 5: Other Common Adverse Reactions (>=2%for all doses of Guanfacine Extended-Release and rate than in placebo) in Fixed Dose Studies and G uanfacine xtended- elease (mg) Adverse Reaction Term Placebo (N=149) mg (N=61) mg (N=150) mg (N=151) mg (N=151) All Doses of uanfacine xtended- elease (N=513) Headache 19% 26% 25% 16% 28% 23% Abdominal Pain 9% 10% 7% 11% 15% 11% Decreased Appetite 4% 5% 4% 9% 6% 6% Irritability 4% 5% 8% 3% 7% 6% Constipation 1% 2% 2% 3% 4% 3% Nightmare 0% 0% 0% 3% 4% 2% Enuresis 1% 0% 1% 3% 2% 2% Affect Lability 1% 2% 1% 3% 1% 2% Adverse reactions >= 2% for all doses of guanfacine extended-release and rate in placebo in any dose group but did not meet this criteria in all doses combined: insomnia (insomnia, initial insomnia, middle insomnia, terminal insomnia, sleep disorder), vomiting, diarrhea, abdominal/stomach discomfort (abdominal discomfort, epigastric discomfort, stomach discomfort), rash (rash, rash generalized, rash papular), dyspepsia, increased weight, bradycardia (bradycardia, sinus bradycardia), asthma (asthma, bronchospasm, wheezing), agitation, anxiety (anxiety, nervousness), sinus arrhythmia, blood pressure increased (blood pressure increased, blood pressure diastolic increased), and first degree atrioventricular block. The lowest dose of mg used in Study was not randomized to patients weighing more than 50 kg. aThe abdominal pain term includes abdominal pain, abdominal pain lower, abdominal pain upper, and abdominal tenderness. bThe nightmare term includes abnormal dreams, nightmare, and sleep terror. cThe enuresis term includes enuresis, nocturia, and urinary incontinence. dThe affect lability term includes affect lability and mood swings. Monotherapy Flexible Dose TrialsTable 6: Percentage of Patients Experiencing Most Common (>=5% and at least twice the rate for placebo) Adverse Reactions in the Monotherapy Flexible Dose Study G uanfacine xtended- elease Adverse Reaction Term Placebo (N=112) AM (N=107) PM (N=114) All Doses of uanfacine xtended- elease (N =221) Somnolence 15% 57% 54% 56% Abdominal Pain 7% 8% 19% 14% Fatigue 3% 10% 11% 11% Irritability 3% 7% 7% 7% Nausea 1% 6% 5% 5% Dizziness 3% 6% 4% 5% Vomiting 2% 7% 4% 5% Hypotension 0% 6% 4% 5% Decreased Appetite 3% 6% 3% 4% Enuresis 1% 2% 5% 4% aThe somnolence term includes somnolence, sedation, and hypersomnia. bThe abdominal pain term includes abdominal pain, abdominal pain lower, abdominal pain upper, and abdominal tenderness cThe hypotension term includes hypotension, diastolic hypotension, orthostatic hypotension, blood pressure decreased, blood pressure diastolic decreased, blood pressure systolic decreased). dThe enuresis term includes enuresis, nocturia, and urinary incontinence. Table 7: Adverse Reactions Leading to Discontinuation (>=2% for all doses of Guanfacine Extended-Release and rate than in placebo) in Monotherapy Flexible Dose Study G uanfacine xtended- elease Adverse Reaction Term Placebo (N=112) AM (N=107) PM (N=114) All Doses of uanfacine xtended- elease (N=221) (%) (%) (%) (%) Total patients (0%) (7%) (6%) 15 (7%) Somnolence 0 (0%) (4%) (3%) (3%) Adverse reactions leading to discontinuation in greater than or equal to 2% in any dose group bud did not meet this criteria in all doses combined: fatigue aThe somnolence term includes somnolence, sedation, and hypersomnia. Table 8: Other Common Adverse Reactions (>=2% for all doses of Guanfacine Extended-Release and rate than in placebo) in the Monotherapy Flexible Dose Study G uanfacine xtended- elease Adverse Reaction Term Placebo (N=112) AM (N=107) PM (N=114) All Doses of uanfacine xtended- elease (N=221) Headache 11% 18% 16% 17% Insomnia 6% 8% 6% 7% Diarrhea 4% 4% 6% 5% Lethargy 0% 4% 3% 3% Constipation 2% 2% 4% 3% Dry Mouth 1% 3% 3% 3% Adverse reactions >= 2% for all doses of guanfacine extended-release and rate in placebo in any dose group but did not meet this criteria in all doses combined: affect lability (affect lability, mood swings), increased weight, syncope/loss of consciousness (loss of consciousness, presyncope, syncope), dyspepsia, tachycardia (tachycardia, sinus tachycardia), and bradycardia (bradycardia, sinus bradycardia). aThe insomnia term includes insomnia, initial insomnia, middle insomnia, terminal insomnia, and sleep disorder. Adjunctive TrialTable 11: Percentage of Patients Experiencing Most Common (>=5% and at least twice the rate for placebo) Adverse Reactions in the Short-Term Adjunctive Study G uanfacine xtended- elease stimulant Adverse Reaction Term Placebo+ stimulant (N=153) AM (N=150) PM (N=152) All Doses (N=302) Somnolence 7% 18% 18% 18% Insomnia 6% 10% 14% 12% Abdominal Pain 3% 8% 12% 10% Fatigue 3% 12% 7% 10% Dizziness 4% 10% 5% 8% Decreased Appetite 4% 7% 8% 7% Nausea 3% 3% 7% 5% aThe somnolence term includes somnolence, sedation, and hypersomnia. bThe insomnia term includes insomnia, initial insomnia, middle insomnia, terminal insomnia, and sleep disorder. cThe abdominal pain term includes abdominal pain, abdominal pain lower, abdominal pain upper, and abdominal tenderness. There were no specific adverse reactions greater than or equal to 2% in any treatment group that led to discontinuation in the short-term adjunctive study (Study 3).Table 12: Other Common Adverse Reactions (>=2% for all doses of Guanfacine Extended-Release and rate than in placebo) in the Short-Term Adjunctive Study G uanfacine xtended- elease stimulant Adverse Reaction Term Placebo (N=153) AM (N=150) PM (N=152) All Doses of uanfacine xtended- elease (N=302) Headache 13% 21% 21% 21% Diarrhea 1% 4% 3% 4% Hypotension 0% 4% 2% 3% Constipation 0% 2% 3% 2% Affect Lability 1% 3% 2% 2% Dry Mouth 0% 1% 3% 2% Bradycardia 0% 1% 3% 2% Postural Dizziness 0% 1% 3% 2% Rash 1% 1% 2% 2% Nightmare 1% 2% 1% 2% Tachycardia 1% 2% 1% 2% Adverse reactions greater than or equal to 2% for all doses of guanfacine extended-release and greater than rate in placebo in any dose group but did not meet this criteria in all doses combined: irritability, vomiting, asthma (asthma, bronchospasm, wheezing), and enuresis (enuresis, nocturia, urinary incontinence). aThe hypotension term includes hypotension, diastolic hypotension, orthostatic hypotension, blood pressure decreased, blood pressure diastolic decreased, blood pressure systolic decreased. bThe affect lability term includes affect lability and mood swings. cThe bradycardia term includes bradycardia and sinus bradycardia. dThe rash term includes rash, rash generalized, and rash papular. eThe nightmare term includes abnormal dreams, nightmare, and sleep terror. fThe tachycardia term includes tachycardia and sinus tachycardia. Effects on Blood Pressure and Heart RateIn the monotherapy pediatric, short-term, controlled trials (Studies and 2), the maximum mean changes from baseline in seated systolic blood pressure, diastolic blood pressure, and pulse were -5.4 mmHg, -3.4 mmHg, and -5.5 bpm, respectively, for all doses combined (generally one week after reaching target doses). For the respective fixed doses mg/day, mg/day, mg/day or mg/day the maximum mean changes in seated systolic blood pressure were -4.3 mmHg, -5.5 mmHg, -5.4 mmHg and -8.2 mmHg. For these respective fixed doses the maximum mean changes in seated diastolic blood pressure were -3.4 mmHg, -3.3 mmHg, -4.4 mmHg and -5.4 mmHg. For these respective fixed doses the maximum mean changes in seated pulse were -4.8 bpm, -3.1 bpm, -6.5 bpm and -8.6 bpm. Decreases in blood pressure and heart rate were usually modest and asymptomatic; however, hypotension and bradycardia can occur. Hypotension was reported as an adverse reaction for 7% of the guanfacine extended-release group and 3% of the placebo group. This includes orthostatic hypotension, which was reported for 1% of the guanfacine extended-release group and none in the placebo group. These findings were generally similar in the monotherapy flexible dose trial (Study 4). In the adjunctive trial, hypotension (3%) and bradycardia (2%) were observed in patients treated with guanfacine extended-release as compared to none in the placebo group. In long-term, open-label studies, (mean exposure of approximately 10 months), maximum decreases in systolic and diastolic blood pressure occurred in the first month of therapy. Decreases were less pronounced over time. Syncope occurred in 1% of pediatric patients in the clinical program. The majority of these cases occurred in the long-term, open-label studies.Effects on Height, Weight, and Body Mass Index (BMI)Patients taking guanfacine extended-release demonstrated similar growth compared to normative data. Patients taking guanfacine extended-release had mean increase in weight of 0.5 kg compared to those receiving placebo over comparable treatment period. Patients receiving guanfacine extended-release for at least 12 months in open-label studies gained an average of kg in weight and cm (3 in) in height. The height, weight, and BMI percentile remained stable in patients at 12 months in the long-term studies compared to when they began receiving guanfacine extended-release.Other Adverse Reactions Observed in Clinical StudiesTable 13 includes additional adverse reactions observed in short-term, placebo-controlled and long-term, open-label clinical studies not included elsewhere in section 6.1, listed by organ system.Table 13: Other Adverse Reactions Observed in Clinical Studies Body System Adverse Reaction Cardiac Atrioventricular block General Asthenia, chest pain Immune System Disorders Hypersensitivity Investigations Increased alanine amino transferase Nervous system Convulsion Renal Increased urinary frequency Vascular Hypertension, pallorAdditional pediatric use information for patients ages to 17 years is approved for Shire US Inc.s INTUNIV(R) (guanfacine) extended-release tablet product. However, due to Shire US Inc.s marketing exclusivity rights, this drug product is not labeled with that pediatric information.

DOSAGE & ADMINISTRATION SECTION.

2 DOSAGE AND ADMINISTRATION. Recommended dose: mg to mg (0.05 mg/kg to 0.12 mg/kg target weight based dose range) once daily in the morning or evening based on clinical response and tolerability 2.2). Begin at dose of mg once daily and adjust in increments of no more than mg/week 2.2). Do not crush, chew or break tablets before swallowing 2.1). Do not administer with high-fat meals, because of increased exposure 2.1). Do not substitute for immediate-release guanfacine tablets on mg-per-mg basis, because of differing pharmacokinetic profiles 2.3). If switching from immediate-release guanfacine, discontinue that treatment and titrate with guanfacine extended-release as directed 2.3). When discontinuing, taper the dose in decrements of no more than mg every to days to avoid rebound hypertension 2.5). Recommended dose: mg to mg (0.05 mg/kg to 0.12 mg/kg target weight based dose range) once daily in the morning or evening based on clinical response and tolerability 2.2). Begin at dose of mg once daily and adjust in increments of no more than mg/week 2.2). Do not crush, chew or break tablets before swallowing 2.1). Do not administer with high-fat meals, because of increased exposure 2.1). Do not substitute for immediate-release guanfacine tablets on mg-per-mg basis, because of differing pharmacokinetic profiles 2.3). If switching from immediate-release guanfacine, discontinue that treatment and titrate with guanfacine extended-release as directed 2.3). When discontinuing, taper the dose in decrements of no more than mg every to days to avoid rebound hypertension 2.5). 2.1 General Instruction for Use. Swallow tablets whole. Do not crush, chew, or break tablets because this will increase the rate of guanfacine release. Do not administer with high fat meals, due to increased exposure. 2.2 Dose Selection. Take guanfacine extended-release tablets orally once daily, either in the morning or evening, at approximately the same time each day. Begin at dose of mg/day, and adjust in increments of no more than mg/week.In monotherapy-clinical trials, there was dose- and exposure-related clinical improvement as well as risks for several clinically significant adverse reactions (hypotension, bradycardia, sedative events). To balance the exposure-related potential benefits and risks, the recommended target dose range depending on clinical response and tolerability for guanfacine extended-release is 0.05 to 0.12 mg/kg/day (total daily dose between mg to mg). In the adjunctive trial which evaluated guanfacine extended-release treatment with psychostimulants, the majority of patients reached optimal doses in the 0.05 to 0.12 mg/kg/day range. Doses above mg/day have not been studied in adjunctive trials.Additional pediatric use information for patients ages to 17 years is approved for Shire US Inc.s INTUNIV(R) (guanfacine) extended-release tablet product. However, due to Shire US Inc.s marketing exclusivity rights, this drug product is not labeled with that pediatric information.. 2.3 Switching from Immediate-Release Guanfacine to Guanfacine Extended-Release. If switching from immediate-release guanfacine, discontinue that treatment, and titrate with guanfacine extended-release following above recommended schedule.Do not substitute for immediate-release guanfacine tablets on milligram-per-milligram basis, because of differing pharmacokinetic profiles. Guanfacine extended-release has significantly reduced max (60% lower), bioavailability (43% lower), and delayed max (3 hours later) compared to those of the same dose of immediate-release guanfacine [see Clinical Pharmacology 12.3 )]. 2.4 Maintenance Treatment. Pharmacological treatment of ADHD may be needed for extended periods. Healthcare providers should periodically re-evaluate the long-term use of guanfacine extended-release, and adjust weight-based dosage as needed. The majority of children and adolescents reach optimal doses in the 0.05 to 0.12 mg/kg/day range.Additional pediatric use information for patients ages to 17 years is approved for Shire US Inc.s INTUNIV(R) (guanfacine) extended-release tablet product. However, due to Shire US Inc.s marketing exclusivity rights, this drug product is not labeled with that pediatric information.. 2.5 Discontinuation of Treatment. Following discontinuation of guanfacine extended-release, patients may experience increases in blood pressure and heart rate [see Warnings and Precautions (5.4) and Adverse Reaction (6) ]. Patients/caregivers should be instructed not to discontinue guanfacine extended-release without consulting their health care provider. Monitor blood pressure and pulse when reducing the dose or discontinuing the drug. Taper the daily dose in decrements of no more than mg every to days to avoid rebound hypertension. 2.6 Missed Doses. When reinitiating patients to the previous maintenance dose after two or more missed consecutive doses, consider titration based on patient tolerability.. 2.7 Dosage Adjustment with Concomitant Use of Strong and Moderate CYP3A4 Inhibitors or Inducers. Dosage adjustments for guanfacine extended-release are recommended with concomitant use of strong and moderate CYP3A4 inhibitors (e.g., ketoconazole), or CYP3A4 inducers (e.g., carbamazepine) (Table 2) [see Drug Interactions 7 )]. Table 2: Guanfacine Extended-Release Dosage Adjustments for Patients Taking Concomitant CYP3A4 Inhibitors or Inducers Clinical Scenarios Starting guanfacine extended-release while currently on CYP3A4 modulator Continuing guanfacine extended- release while adding CYP3A4 modulator Continuing guanfacine extended-release while stopping CYP3A4 modulator CYP3A4 Strong and oderate Inhibitors Decrease guanfacine extended-release dosage to half the recommended level. Decrease guanfacine extended-release dosage to half the recommended level. Increase guanfacine extended-release dosage to recommended level. CYP3A4 Strong and oderate Inducers Consider increasing guanfacine extended- release dosage up to double the recommended level. Consider increasing guanfacine extended-release dosage up to double the recommended level over to weeks. Decrease guanfacine extended-release dosage to recommended level over to weeks.

PHARMACOKINETICS SECTION.

12.3 Pharmacokinetics. Absorption and DistributionGuanfacine is readily absorbed and approximately 70% bound to plasma proteins independent of drug concentration. After oral administration of guanfacine extended-release the time to peak plasma concentration is approximately hours in children and adolescents with ADHD.Immediate-release guanfacine and guanfacine extended-release have different pharmacokinetic characteristics; dose substitution on milligram per milligram basis will result in differences in exposure.A comparison across studies suggests that the max is 60% lower and AUC 0- 43% lower, respectively, for guanfacine extended-release compared to immediate-release guanfacine. Therefore, the relative bioavailability of guanfacine extended-release to immediate-release guanfacine is 58%. The mean pharmacokinetic parameters in adults following the administration of guanfacine extended-release mg once daily and immediate-release guanfacine mg once daily are summarized in Table 15. Table 15: Comparison of Pharmacokinetics: Guanfacine Extended-Release vs. Immediate release Guanfacine in Adults Parameter uanfacine xtended- elease mg once daily (n=52) Immediate- elease uanfacine mg once daily (n=12) max (ng/mL) 1.0 +- 0.3 2.5 +- 0.6 AUC 0- (ng.h/mL) 32 +- 56 +- 15 max (h) 6.0 (4.0 8.0) 3.0 (1.5-4.0) 1/2 (h) 18 +- 16 +- 3Note: Values are mean +/- SD, except for max which is median (range) Figure 1: Comparison of Pharmacokinetics: Guanfacine Extended-Release vs. Immediate-release Guanfacine in Adults Exposure to guanfacine was higher in children (ages to 12) compared to adolescents (ages 13 to 17) and adults. After oral administration of multiple doses of guanfacine extended-release mg, the max was 10 ng/mL compared to ng/mL and the AUC was 162 ngoh/mL compared to 116 ngoh/mL in children (ages to 12) and adolescents (ages 13 to 17), respectively. These differences are probably attributable to the lower body weight of children compared to adolescents and adults. The pharmacokinetics were affected by intake of food when single dose of guanfacine extended-release mg was administered with high-fat breakfast. The mean exposure increased (C max ~75% and AUC ~40%) compared to dosing in fasted state. Dose ProportionalityFollowing administration of guanfacine extended-release in single doses of mg, mg, mg, and mg to adults, max and AUC 0- of guanfacine were proportional to dose. Metabolism and EliminationIn vitro studies with human liver microsomes and recombinant CYPs demonstrated that guanfacine was primarily metabolized by CYP3A4. In pooled human hepatic microsomes, guanfacine did not inhibit the activities of the major cytochrome P450 isoenzymes (CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6 or CYP3A4/5). Guanfacine is substrate of CYP3A4/5 and exposure is affected by CYP3A4/5 inducers/inhibitors. Studies in Specific PopulationsRenal ImpairmentThe impact of renal impairment on the pharmacokinetics of guanfacine in children was not assessed. In adult patients with impaired renal function, the cumulative urinary excretion of guanfacine and the renal clearance diminished as renal function decreased. In patients on hemodialysis, the dialysis clearance was about 15% of the total clearance. The low dialysis clearance suggests that the hepatic elimination (metabolism) increases as renal function decreases.Hepatic ImpairmentThe impact of hepatic impairment on PK of guanfacine in children was not assessed. Guanfacine in adults is cleared both by the liver and the kidney, and approximately 50% of the clearance of guanfacine is hepatic [see Hepatic Impairment 8.7 )]. Drug Interaction StudiesGuanfacine is primarily metabolized by CYP3A4 and its plasma concentrations can be affected significantly by CYP3A4 inhibitors or inducers (Figure 2).Guanfacine does not significantly affect exposures of methylphenidate and lisdexamfetamine when coadministered (Figure 3).. correct-figure. Figure 2: Effect of Other Drugs on the Pharmacokinetics (PK) of Guanfacine Extended-Release. Figure 3: Effect of Guanfacine Extended-Release on the Pharmacokinetics (PK) of Other Drugs.

SPL PATIENT PACKAGE INSERT SECTION.

Patient Information. Guanfacine (gwahn fa seen)Extended-Release TabletsRx Only Read the Patient Information that comes with guanfacine extended-release before you start taking it and each time you get refill. There may be new information. This leaflet does not take the place of talking with your doctor about your medical condition or your treatment. What areguanfacine extended-release tabletsGuanfacine extended-release tablets are prescription medicine used to treat the symptoms of attention deficit hyperactivity disorder (ADHD). Guanfacine extended-release tablets may be used alone or with ADHD stimulant medicines.Guanfacine extended-release is not central nervous system (CNS) stimulant.It is not known if guanfacine extended-release tablets are safe and effective in children younger than years of age.Who should not take guanfacine extended-release tabletsDo not take guanfacine extended-release tablets if you are allergic to guanfacine or any of the ingredients in guanfacine extended-release tablets. See the end of this leaflet for complete list of ingredients in guanfacine extended-release tablets.What should tell my doctor before taking guanfacine extended-release tabletsBefore you take guanfacine extended-release tablets, tell your doctor if you:have heart problems or low heart ratehave faintedhave low or high blood pressurehave liver or kidney problemshave any other medical conditionsare pregnant or plan to become pregnant. It is not known if guanfacine extended-release tablets will harm your unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant.are breastfeeding or plan to breastfeed. It is not known if guanfacine passes into your breast milk. Talk to your doctor about the best way to feed your baby while taking guanfacine extended-release.Tell your doctor about all of the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.Guanfacine extended-release tablets may affect the way other medicines work, and other medicines may affect how guanfacine extended-release tablets work.Especially tell your doctor if you take:ketoconazolemedicines that can affect enzyme metabolismhigh blood pressure medicinesedativesbenzodiazepinesbarbituratesantipsychoticsAsk your doctor or pharmacist for list of these medicines, if you are not sure.Know the medicines you take. Keep list of them and show it to your doctor and pharmacist when you get new medicine.How should takeguanfacine extended-release tabletsTake guanfacine extended-release tablets exactly as your doctor tells you.Your doctor may change your dose. Do not change your dose of guanfacine extended-release tablets without talking to your doctor.Try not to miss your dose of guanfacine extended-release tablets. If you miss dose of guanfacine extended-release tablets, take the next dose at your regular time. If you miss or more doses, talk to your doctor, as you may need to restart guanfacine extended-release tablets with lower dose.Do not take double dose to make up for missed dose.Do not stop taking guanfacine extended-release tablets without talking to your doctor.Guanfacine extended-release tablets should be taken time day in the morning or in the evening, either alone or in combination with an ADHD stimulant medicine that your doctor may prescribe. Your doctor will tell you when to take guanfacine extended-release tablets and when to take your ADHD stimulant medication.Guanfacine extended-release tablets should be swallowed whole with small amount of water, milk, or other liquid.Do not crush, chew, or break guanfacine extended-release tablets. Tell your doctor if you cannot swallow guanfacine extended-release tablets whole.Do not take guanfacine extended-release tablets with high-fat meal. Your doctor will check your blood pressure and heart rate while you take guanfacine extended-release tablets.If you take too many guanfacine extended-release tablets, call your local Poison Control Center at 1-800-222-1222 or go to the nearest emergency room right away. What should avoid while taking guanfacine extended-release tabletsDo not drive, operate heavy machinery, or do other dangerous activities until you know how guanfacine extended-release tablets affect you. Guanfacine extended-release tablets can slow your thinking and motor skills.Do not drink alcohol or take other medicines that make you sleepy or dizzy while taking guanfacine extended-release tablets until you talk with your doctor. Guanfacine extended-release tablets taken with alcohol or medicines that cause sleepiness or dizziness may make your sleepiness or dizziness worse.Do not become dehydrated or overheated. This may increase your chance of having low blood pressure or fainting while taking guanfacine extended-release tablets.Do not suddenly stop guanfacine extended-release tablets. Tell your healthcare provider if you have been vomiting and cannot take guanfacine extended-release tablets, you may be at risk for rebound hypertension.What are the possible side effects of guanfacine extended-release tabletsGuanfacine extended-release tabletsmay cause serious side effects including:low blood pressurelow heart ratefaintingsleepinessincreased blood pressure and heart rate after suddenly stopping guanfacine extended-release tablets (rebound hypertension). Suddenly stopping guanfacine extended-release tablets can cause increased blood pressure and heart rate and other withdrawal symptoms such as headache, confusion, nervousness, agitation, and tremors. If these symptoms continue to get worse and are left untreated, it could lead to very serious condition including very high blood pressure, feeling very sleepy or tired, severe headache, vomiting, vision problems, seizures.Get medical help right away, if you have any of the symptoms listed above.The most common side effects of guanfacine extended-release tablets include:sleepinesstirednesstrouble sleepinglow blood pressurenauseastomach paindizzinessdry mouthirritabilityvomitingslow heart rateTell the doctor if you have any side effect that bothers you or that does not go away.These are not all the possible side effects of guanfacine extended-release tablets. For more information, ask your doctor or pharmacist.Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.How should storeguanfacine extended-release tabletsStore guanfacine extended-release tablets between 68F to 77F (20C to 25C)Keep guanfacine extended-release tablets and all medicines out of the reach of children. General Information about the safe and effective use guanfacine extended-release tabletsMedicines are sometimes prescribed for purposes other than those listed in Patient Information Leaflet. Do not use guanfacine extended-release tablets for condition for which they were not prescribed. Do not give guanfacine extended-release tablets to other people, even if they have the same symptoms that you have. It may harm them.This leaflet summarizes the most important information about guanfacine extended-release tablets. If you would like more information, talk with your doctor. You can ask your pharmacist or doctor for information about guanfacine extended-release tablets that is written for health professionals.For more information, call AvKARE, Inc. at 1-855-361-3993.What are the ingredients in guanfacine extended-release tablets Active ingredient: guanfacine hydrochloride Inactive ingredients: colloidal silicon dioxide, crospovidone, fumaric acid, glyceryl behenate, hydroxypropyl cellulose, hypromellose, lactose monohydrate, microcrystalline cellulose, and povidone. In addition, the mg and mg tablets contain FD&C Yellow Aluminum Lake and the mg and mg tablets contain D&C Yellow 10 Aluminum Lake. This Patient Information has been approved by the U.S. Food and Drug Administration.Manufactured for: AvKARE, Inc. Pulaski, TN 38478 Mfg. Rev. 01/18 AV Rev. 10/18 (P) have heart problems or low heart rate. have fainted. have low or high blood pressure. have liver or kidney problems. have any other medical conditions. are pregnant or plan to become pregnant. It is not known if guanfacine extended-release tablets will harm your unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant.. are breastfeeding or plan to breastfeed. It is not known if guanfacine passes into your breast milk. Talk to your doctor about the best way to feed your baby while taking guanfacine extended-release.. ketoconazole. medicines that can affect enzyme metabolism. high blood pressure medicine. sedatives. benzodiazepines. barbiturates. antipsychotics. Take guanfacine extended-release tablets exactly as your doctor tells you.. Your doctor may change your dose. Do not change your dose of guanfacine extended-release tablets without talking to your doctor.. Try not to miss your dose of guanfacine extended-release tablets. If you miss dose of guanfacine extended-release tablets, take the next dose at your regular time. If you miss or more doses, talk to your doctor, as you may need to restart guanfacine extended-release tablets with lower dose.. Do not take double dose to make up for missed dose.. Do not stop taking guanfacine extended-release tablets without talking to your doctor.. Guanfacine extended-release tablets should be taken time day in the morning or in the evening, either alone or in combination with an ADHD stimulant medicine that your doctor may prescribe. Your doctor will tell you when to take guanfacine extended-release tablets and when to take your ADHD stimulant medication.. Guanfacine extended-release tablets should be swallowed whole with small amount of water, milk, or other liquid.. Do not crush, chew, or break guanfacine extended-release tablets. Tell your doctor if you cannot swallow guanfacine extended-release tablets whole.. Do not take guanfacine extended-release tablets with high-fat meal. Your doctor will check your blood pressure and heart rate while you take guanfacine extended-release tablets.. If you take too many guanfacine extended-release tablets, call your local Poison Control Center at 1-800-222-1222 or go to the nearest emergency room right away. Do not drive, operate heavy machinery, or do other dangerous activities until you know how guanfacine extended-release tablets affect you. Guanfacine extended-release tablets can slow your thinking and motor skills.. Do not drink alcohol or take other medicines that make you sleepy or dizzy while taking guanfacine extended-release tablets until you talk with your doctor. Guanfacine extended-release tablets taken with alcohol or medicines that cause sleepiness or dizziness may make your sleepiness or dizziness worse.. Do not become dehydrated or overheated. This may increase your chance of having low blood pressure or fainting while taking guanfacine extended-release tablets.. Do not suddenly stop guanfacine extended-release tablets. Tell your healthcare provider if you have been vomiting and cannot take guanfacine extended-release tablets, you may be at risk for rebound hypertension.. low blood pressure. low heart rate. fainting. sleepiness. increased blood pressure and heart rate after suddenly stopping guanfacine extended-release tablets (rebound hypertension). Suddenly stopping guanfacine extended-release tablets can cause increased blood pressure and heart rate and other withdrawal symptoms such as headache, confusion, nervousness, agitation, and tremors. If these symptoms continue to get worse and are left untreated, it could lead to very serious condition including very high blood pressure, feeling very sleepy or tired, severe headache, vomiting, vision problems, seizures.. sleepiness. tiredness. trouble sleeping. low blood pressure. nausea. stomach pain. dizziness. dry mouth. irritability. vomiting. slow heart rate. Store guanfacine extended-release tablets between 68F to 77F (20C to 25C).