ADVERSE REACTIONS SECTION.

ADVERSE REACTIONS. Infusion-Related Events. During or soon after rapid infusion of vancomycin, patients may develop anaphylactoid reactions, including hypotension (see ANIMAL PHARMACOLOGY), wheezing, dyspnea, urticaria, or pruritus. Rapid infusion may also cause flushing of the upper body (red neck) or pain and muscle spasms of the chest and back. These reactions usually resolve within 20 minutes but may persist for several hours. Such events are infrequent if vancomycin is given by slow infusion over 60 minutes. In studies of normal volunteers, infusion-related events did not occur when vancomycin was administered at rate of 10 mg/min or less.. Nephrotoxicity. Renal failure, principally manifested by increased serum creatinine or BUN concentrations, especially in patients administered large doses of vancomycin, has been reported rarely. Cases of interstitial nephritis have also been reported rarely. Most of these have occurred in patients who were given aminoglycosides concomitantly or who had preexisting kidney dysfunction. When vancomycin was discontinued, azotemia resolved in most patients.. Gastrointestinal. Onset of pseudomembranous colitis symptoms may occur during or after antibiotic treatment (see WARNINGS).. Ototoxicity. few dozen cases of hearing loss associated with vancomycin have been reported. Most of these patients had kidney dysfunction or preexisting hearing loss or were receiving concomitant treatment with an ototoxic drug. Vertigo, dizziness, and tinnitus have been reported rarely.. Hematopoietic. Reversible neutropenia, usually starting week or more after onset of therapy with vancomycin or after total dosage of more than 25 g, has been reported for several dozen patients. Neutropenia appears to be promptly reversible when vancomycin is discontinued. Thrombocytopenia has rarely been reported. Although casual relationship has not been established, reversible agranulocytosis (granulocytes <500/mm3) has been reported rarely.. Phlebitis. Inflammation at the injection site has been reported.. Miscellaneous. Infrequently, patients have been reported to have had anaphylaxis, drug fever, nausea, chills, eosinophilia, rashes including exfoliative dermatitis, linear IgA bullous dermatosis, Stevens-Johnson syndrome, toxic epidermal necrolysis and vasculitis in association with administration of vancomycin.Chemical peritonitis has been reported following intraperitoneal administration of vancomycin (see PRECAUTIONS).. Post Marketing Reports. The following adverse reactions have been identified during post-approval use of vancomycin. Because these reactions are reported voluntarily from population of uncertain size, it is not possible to reliably estimate their frequency or establish causal relationship to drug exposure. Skin and Subcutaneous Tissue Disorders Drug Rash with Eosinophilia and Systemic Symptoms (DRESS).

CLINICAL PHARMACOLOGY SECTION.

CLINICAL PHARMACOLOGY. Vancomycin is poorly absorbed after oral administration; it is given intravenously for therapy of systemic infections. In subjects with normal kidney function, multiple intravenous dosing of g of vancomycin (15 mg/kg) infused over 60 minutes produces mean plasma concentrations of approximately 63 mcg/mL immediately after the completion of infusion, mean plasma concentrations of approximately 23 mcg/mL hours after infusion, and mean plasma concentrations of approximately mcg/mL 11 hours after the end of infusion. Multiple dosing of 500 mg infused over 30 minutes produces mean plasma concentrations of about 49 mcg/mL at the completion of infusion, mean plasma concentrations of about 19 mcg/mL hours after infusion, and mean plasma concentrations of about 10 mcg/mL hours after infusion. The plasma concentrations during multiple dosing are similar to those after single dose. The mean elimination half-life of vancomycin from plasma is to hours in subjects with normal renal function. In the first 24 hours, about 75% of an administered dose of vancomycin is excreted in urine by glomerular filtration. Mean plasma clearance is about 0.058 L/kg/h, and mean renal clearance is about 0.048 L/kg/h. Renal dysfunction slows excretion of vancomycin. In anephric patients, the average half-life of elimination is 7.5 days. The distribution coefficient is from 0.3 to 0.43 L/kg. There is no apparent metabolism of the drug. About 60% of an intraperitoneal dose of vancomycin administered during peritoneal dialysis is absorbed systemically in hours. Serum concentrations of about 10 mcg/mL are achieved by intraperitoneal injection of 30 mg/kg of vancomycin. However, the safety and efficacy of the intraperitoneal use of vancomycin has not been established in adequate and well-controlled trials (see PRECAUTIONS).Total systemic and renal clearance of vancomycin may be reduced in the elderly. Vancomycin is approximately 55% serum protein bound as measured by ultrafiltration at vancomycin serum concentrations of 10 to 100 mcg/mL. After IV administration of vancomycin, inhibitory concentrations are present in pleural, pericardial, ascitic, and synovial fluids; in urine; in peritoneal dialysis fluid; and in atrial appendage tissue. Vancomycin does not readily diffuse across normal meninges into the spinal fluid; but, when the meninges are inflamed, penetration into the spinal fluid occurs.. Microbiology. The bactericidal action of vancomycin results primarily from inhibition of cell-wall biosynthesis. In addition, vancomycin alters cell membrane permeability and RNA synthesis. There is no cross-resistance between vancomycin and other antibiotics. Vancomycin is not active in vitro against gram-negative bacilli, mycobacteria, or fungi.. Synergy. The combination of vancomycin and an aminoglycoside acts synergistically in vitro against many strains of Staphylococcus aureus, Streptococcus bovis, enterococci and the viridans group streptococci. Vancomycin has been shown to be active against most strains of the following microorganisms, both in vitro and in clinical infections as described in the INDICATIONS AND USAGE section.. Aerobic gram-positive microorganisms. DiphtheroidsEnterococci (e.g., Enterococcus faecalis)Staphylococci, including Staphylococcus aureus and Staphylococcus epidermidis (including heterogeneous methicillin-resistant strains)Streptococcus bovisViridans group streptococciThe following in vitro data are available, but their clinical significance is unknown Vancomycin exhibits in vitro MICs of mcg/mL or less against most (>=90%) strains of streptococci listed below and MICs of mcg/mL or less against most (>=90%) strains of other listed microorganisms; however, the safety and effectiveness of vancomycin in treating clinical infections due to these microorganisms have not been established in adequate and well-controlled clinical trials.. Aerobic gram-positive microorganisms. Listeria monocytogenesStreptococcus pyogenesStreptococcus pneumoniae (including penicillin-resistant strains)Streptococcus agalactiae. Anaerobic gram-positive microorganisms. Actinomyces speciesLactobacillus species. Susceptibility Test Methods. When available, the clinical microbiology laboratory should provide the results of in vitro susceptibility test results for antimicrobial drugs used in local hospitals and practice areas to the physician as periodic reports that describe the susceptibility profile of nosocomial and community-acquired pathogens. These reports should aid the physician in selecting the most effective antimicrobial.. Dilution Techniques. Quantitative methods are used to determine antimicrobial minimum inhibitory concentrations (MICs). These MICs provide estimates of the susceptibility of bacteria to antimicrobial compounds. The MICs should be determined using standardized procedure. Standardized procedures are based on dilution method1,2 (broth, agar or microdilution) or equivalent using standardized inoculum and concentrations of vancomycin powder. The MIC values should be interpreted according to the criteria in Table 1.. Diffusion Techniques. Quantitative methods that require measurement of zone diameters also provide reproducible estimates of the susceptibility of bacteria to antimicrobial compounds. One such standardized procedure2,3 requires the use of standardized inoculum concentrations. This procedure uses paper disks impregnated with 30 mcg of vancomycin to test the susceptibility of microorganisms to vancomycin. Interpretation involves correlation of the diameter obtained in the disk test with the MIC for vancomycin. Reports from the laboratory providing results of the standard single-disk susceptibility test with 30 mcg vancomycin disk should be interpreted according to the following criteria in Table 1.Table 1. Susceptibility Test Interpretive Criteria for VancomycinMinimum Inhibitory Concentrations (mcg/mL)Disk Diffusion Diameters (mm)PathogenSusceptible (S)Intermediate (I)Resistant (R)Susceptible (S)Intermediate (I)Resistant (R)EnterococciA ss-lactamase test using an inoculum >= 107 CFU/mL or direct colony growth and nitrocefin-based substrate should be performed to detect either ampicillin or penicillin resistance due to ss-lactamase production. <=4 - 16 >=32 >=17Plates should be held for full 24 hours and examined using transmitted light. The presence of haze or any growth within the zone of inhibition indicates resistance. Those enterococci with intermediate zones of inhibition should be tested by standardized procedure based on dilution method1 2 (broth or agar) or equivalent. 15 16 <=14 Staphylococcus aureus<=2 - >=16 >=15The current absence of resistant isolates precludes defining results other than Susceptible. Isolates yielding results suggestive of Nonsusceptible should be submitted to reference laboratory for further testing. - Coagulase-negative staphylococci <=4 - 16 >=32 >=15 - Streptococci other than . pneumoniae <=1 Interpretative criteria applicable only to tests performed by broth microdilution method using cation-adjusted Mueller-Hinton broth with to 5% lysed horse blood1 2. - >=17 Interpretative criteria applicable only to tests performed by disk diffusion method using Mueller-Hinton agar with 5% defibrinated sheep blood and incubated in 5% CO2 3. - report of Susceptible indicates that the pathogen is likely to be inhibited if the antimicrobial compound in the blood reaches the concentrations usually achievable. report of Intermediate indicates that the result should be considered equivocal, and if the microorganism is not fully susceptible to alternative, clinically feasible drugs, the test should be repeated. This category implies possible clinical applicability in body sites where the drug is physiologically concentrated or in situations where high dosage of drug can be used. This category also provides buffer zone which prevents small uncontrolled technical factors from causing major discrepancies in interpretation. report of Resistant indicates that the pathogen is not likely to be inhibited if the antimicrobial compound in the blood reaches the concentrations usually achievable; other therapy should be selected.. Quality Control. Standardized susceptibility test procedures require the use of laboratory control microorganisms to monitor and ensure the accuracy and precision of the supplies and reagents used in the assay, and the techniques of the individuals performing the test. Standard vancomycin powder should provide MIC values provided below. For the diffusion technique, the 30 mcg vancomycin disk should provide the following zone diameters with the quality control strains: Table 2. In Vitro Susceptibility Test Quality Control Ranges for VancomycinOrganism (ATCC) MIC range (mcg/mL) Disk diffusion range (mm) Enterococcus faecalis (29212)1-4 Not applicable Staphylococcus aureus (29213)0.5-2 Not applicable Staphylococcus aureus (25923)Not applicable 17-21 Streptococcus pneumoniae (49619)Interpretative criteria applicable only to tests performed using cation-adjusted Mueller-Hinton broth with to 5% lysed horse blood1. Disk diffusion interpretative criteria applicable only to tests performed using Mueller-Hinton agar with 5% defibrinated sheep blood and incubated in 5% CO2 2.0.12-0.5 20-27.

DOSAGE & ADMINISTRATION SECTION.

DOSAGE AND ADMINISTRATION. Infusion-related events are related to both the concentration and the rate of administration of vancomycin. Concentrations of no more than mg/mL and rates of no more than 10 mg/min are recommended in adults (see also age-specific recommendations). In selected patients in need of fluid restriction, concentration up to 10 mg/mL may be used; use of such higher concentrations may increase the risk of infusion-related events. An infusion rate of 10 mg/min or less is associated with fewer infusion-related events (see ADVERSE REACTIONS). Infusion-related events may occur, however, at any rate or concentration. Patients with normal renal function. Adults. The usual daily intravenous dose is g divided either as 500 mg every hours or g every 12 hours. Each dose should be administered at no more than 10 mg/min or over period of at least 60 minutes, whichever is longer. Other patient factors, such as age or obesity, may call for modification of the usual intravenous daily dose.. Pediatric patients. The usual intravenous dosage of vancomycin is 10 mg/kg per dose given every hours. Each dose should be administered over period of at least 60 minutes. Close monitoring of serum concentrations of vancomycin may be warranted in these patients.. Neonates. In pediatric patients up to the age of month, the total daily intravenous dosage may be lower. In neonates, an initial dose of 15 mg/kg is suggested, followed by 10 mg/kg every 12 hours for neonates in the 1st week of life and every hours thereafter up to the age of month. Each dose should be administered over 60 minutes. In premature infants, vancomycin clearance decreases as postconceptional age decreases. Therefore, longer dosing intervals may be necessary in premature infants. Close monitoring of serum concentrations of vancomycin is recommended in these patients.. Patients with Impaired Renal Function and Elderly Patients. Dosage adjustment must be made in patients with impaired renal function. In the elderly, greater dosage reductions than expected may be necessary because of decreased renal function. Measurement of vancomycin serum concentrations can be helpful in optimizing therapy, especially in seriously ill patients with changing renal function. Vancomycin serum concentrations can be determined by use of microbiologic assay, radioimmunoassay, fluorescence polarization immunoassay, fluorescence immunoassay, or high-pressure liquid chromatography. If creatinine clearance can be measured or estimated accurately, the dosage for most patients with renal impairment can be calculated using the following table. The dosage of vancomycin per day in mg is about 15 times the glomerular filtration rate in mL/min:DOSAGE TABLE FOR VANCOMYCIN IN PATIENTS WITH IMPAIRED RENAL FUNCTION(Adapted from Meollering et al) Creatinine Clearance mL/minVancomycin Dose mg/24 hr100 1,545 90 1,390 80 1,235 70 1,080 60 925 50 770 40 620 30 465 20 310 10 155 The initial dose should be no less than 15 mg/kg, even in patients with mild to moderate renal insufficiency. The table is not valid for functionally anephric patients. For such patients, an initial dose of 15 mg/kg of body weight should be given to achieve prompt therapeutic serum concentrations. The dose required to maintain stable concentrations is 1.9 mg/kg/24 h. In patients with marked renal impairment, it may be more convenient to give maintenance doses of 250 to 1,000 mg once every several days rather than administering the drug on daily basis. In anuria, dose of 1,000 mg every to 10 days has been recommended. When only the serum creatinine concentration is known, the following formula (based on sex, weight, and age of the patient) may be used to calculate creatinine clearance. Calculated creatinine clearances (mL/min) are only estimates. The creatinine clearance should be measured promptly.Men: [Weight (kg) (140-age in years)] [72 serum creatinine concentration (mg/dL)]Women: 0.85 above valueThe serum creatinine must represent steady state of renal function. Otherwise, the estimated value for creatinine clearance is not valid. Such calculated clearance is an overestimate of actual clearance in patients with conditions: (1) characterized by decreasing renal function, such as shock, severe heart failure, or oliguria; (2) in which normal relationship between muscle mass and total body weight is not present, such as obese patients or those with liver disease, edema, or ascites; and (3) accompanied by debilitation, malnutrition, or inactivity. The safety and efficacy of vancomycin administration by the intrathecal (intralumbar or intraventricular) route have not been established.Intermittent infusion is the recommended method of administration.. Preparation and stability. At the time of use, reconstitute by adding either 10 mL of Sterile Water for Injection to the 500-mg vial or 20 mL of Sterile Water for Injection to the 1-g vial of dry, sterile vancomycin powder. FURTHER DILUTION IS REQUIRED.After reconstitution with Sterile Water for Injection, 5% Dextrose Injection, or 0.9% Sodium Chloride Injection, the vials may be stored in refrigerator for 14 days without significant loss of potency.Reconstituted solutions containing 500 mg/10 mL must be further diluted with at least 100 mL of suitable infusion solution. Reconstituted solutions containing g/20 mL must be further diluted with at least 200 mL of suitable infusion solution. The desired dose, diluted in this manner, should be administered by intermittent intravenous infusion over period of at least 60 minutes.. Compatibility with Other Drugs and Intravenous Fluids. Solutions that are diluted with 5% Dextrose Injection or 0.9% Sodium Chloride Injection may be stored in refrigerator for 14 days without significant loss of potency. Solutions that are diluted with the following infusion fluids may be stored in refrigerator for 96 hours:5% Dextrose Injection, USP5% Dextrose and 0.9% Sodium Chloride Injection, USPLactated Ringers Injection, USP Lactated Ringers and 5% Dextrose Injection, USPNormosol(R)-M and 5% Dextrose ISOLYTE(R) EVancomycin solution has low pH and may cause chemical or physical instability when it is mixed with other compounds.Mixtures of solutions of vancomycin and beta-lactam antibiotics have been shown to be physically incompatible. The likelihood of precipitation increases with higher concentrations of vancomycin. It is recommended to adequately flush the intravenous lines between the administration of these antibiotics. It is also recommended to dilute solutions of vancomycin to mg/mL or less.Although intravitreal injection is not an approved route of administration for vancomycin, precipitation has been reported after intravitreal injection of vancomycin and ceftazidime for endophthalmitis using different syringes and needles. The precipitates dissolved gradually, with complete clearing of the vitreous cavity over two months and with improvement of visual acuity.Prior to administration, parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution or container permits.For Oral AdministrationOral vancomycin is used in treating antibiotic-associated pseudomembranous colitis caused by C. difficile and for staphylococcal enterocolitis. Vancomycin is not effective by the oral route for other types of infections. The usual adult total daily dosage is 500 mg to g given in or divided doses for to 10 days. The total daily dose in children is 40 mg/kg of body weight in or divided doses for to 10 days. The total daily dosage should not exceed g. The appropriate dose may be diluted in oz of water and given to the patient to drink. Common flavoring syrups may be added to the solution to improve the taste for oral administration. The diluted solution may be administered via nasogastric tube.

INDICATIONS & USAGE SECTION.

INDICATIONS AND USAGE. Vancomycin is indicated for the treatment of serious or severe infections caused by susceptible strains of methicillin-resistant (beta-lactam-resistant) staphylococci. It is indicated for penicillin-allergic patients, for patients who cannot receive or who have failed to respond to other drugs, including the penicillins or cephalosporins, and for infections caused by vancomycin-susceptible organisms that are resistant to other antimicrobial drugs. Vancomycin is indicated for initial therapy when methicillin-resistant staphylococci are suspected, but after susceptibility data are available, therapy should be adjusted accordingly.Vancomycin hydrochloride is effective in the treatment of staphylococcal endocarditis. Its effectiveness has been documented in other infections due to staphylococci, including septicemia, bone infections, lower respiratory tract infections, and skin and skin-structure infections. When staphylococcal infections are localized and purulent, antibiotics are used as adjuncts to appropriate surgical measures.Vancomycin hydrochloride has been reported to be effective alone or in combination with an aminoglycoside for endocarditis caused by S. viridans or S. bovis. For endocarditis caused by enterococci (e.g., E. faecalis), vancomycin hydrochloride has been reported to be effective only in combination with an aminoglycoside. Vancomycin has been reported to be effective for the treatment of diphtheroid endocarditis. Vancomycin has been used successfully in combination with either rifampin, an aminoglycoside, or both in early-onset prosthetic valve endocarditis caused by S. epidermidis or diphtheroids.Specimens for bacteriologic cultures should be obtained in order to isolate and identify causative organisms and to determine their susceptibilities to vancomycin.The parenteral form of Sterile Vancomycin Hydrochloride may be administered orally for treatment of antibiotic-associated pseudomembranous colitis produced by C. difficile and for staphylococcal enterocolitis. Parenteral administration of vancomycin hydrochloride alone is of unproven benefit for these indications. Vancomycin is not effective by the oral route for other types of infection. To reduce the development of drug-resistant bacteria and maintain the effectiveness of vancomycin and other antibacterial drugs, vancomycin should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

PRECAUTIONS SECTION.

PRECAUTIONS. General. Clinically significant serum concentrations have been reported in some patients being treated for active C. difficile-induced pseudomembranous colitis after multiple oral doses of vancomycin.Prolonged use of vancomycin may result in the overgrowth of non-susceptible microorganisms. Careful observation of the patient is essential. If superinfection occurs during therapy, appropriate measures should be taken. In rare instances, there have been reports of pseudomembranous colitis due to C. difficile developing in patients who received intravenous vancomycin.In order to minimize the risk of nephrotoxicity when treating patients with underlying renal dysfunction or patients receiving concomitant therapy with an aminoglycoside, serial monitoring of renal function should be performed and particular care should be taken in following appropriate dosing schedules (see DOSAGE AND ADMINISTRATION).Serial tests of auditory function may be helpful in order to minimize the risk of ototoxicity.Reversible neutropenia has been reported in patients receiving vancomycin (see ADVERSE REACTIONS). Patients who will undergo prolonged therapy with vancomycin or those who are receiving concomitant drugs which may cause neutropenia should have periodic monitoring of the leukocyte count.Vancomycin is irritating to tissue and must be given by secure intravenous route of administration. Pain, tenderness and necrosis occur with inadvertent extravasation. Thrombophlebitis may occur, the frequency and severity of which can be minimized by slow infusion of the drug and by rotation of venous access sites.There have been reports that the frequency of infusion-related events (including hypotension flushing, erythema, urticaria and pruritus) increases with the concomitant administration of anesthetic agents. Infusion-related events may be minimized by the administration of vancomycin as 60-minute infusion prior to the anesthetic induction. The safety and efficacy of vancomycin administered by the intrathecal (intralumbar or intraventricular) route or by the intraperitoneal route have not been established by adequate and well controlled trials.Reports have revealed that the administration of sterile vancomycin by the intraperitoneal route during continuous ambulatory peritoneal dialysis (CAPD) has resulted in syndrome of chemical peritonitis. To date, this syndrome has ranged from cloudy dialysate alone to cloudy dialysate accompanied by variable degrees of abdominal pain and fever. This syndrome appears to be short-lived after discontinuation of intraperitoneal vancomycin.Prescribing vancomycin in the absence of proven or strongly suspected bacterial infection or prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.Drug Interactions Concomitant administration of vancomycin and anesthetic agents has been associated with erythema and histamine-like flushing (see Usage in Pediatrics under PRECAUTIONS) and anaphylactoid reactions (see ADVERSE REACTIONS). Concurrent and/or sequential systemic or topical use of other potentially, neurotoxic and/or nephrotoxic drugs, such as amphotericin B, aminoglycosides, bacitracin, polymixin B, colistin, viomycin, or cisplatin, when indicated, requires careful monitoring. Pregnancy. Teratogenic Effects: Pregnancy Category C. Animal reproduction studies have not been conducted with vancomycin. It is not known whether vancomycin can affect reproduction capacity. In controlled clinical study, the potential ototoxic and nephrotoxic effects of vancomycin on infants were evaluated when the drug was administered to pregnant women for serious staphylococcal infections complicating intravenous drug abuse. Vancomycin was found in cord blood. No sensorineural hearing loss or nephrotoxicity attributable to vancomycin was noted. One infant whose mother received vancomycin in the third trimester experienced conductive hearing loss that was not attributed to the administration of vancomycin. Because the number of patients treated in this study was limited and vancomycin was administered only in the second and third trimesters, it is not known whether vancomycin causes fetal harm. Vancomycin should be given to pregnant woman only if clearly needed.. Nursing Mothers. Vancomycin is excreted in human milk. Caution should be exercised when vancomycin is administered to nursing woman. Because of the potential for adverse events, decision should be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.. Pediatric use. In pediatric patients, it may be appropriate to confirm desired vancomycin serum concentrations. Concomitant administration of vancomycin and anesthetic agents has been associated with erythema and histamine-like flushing in pediatric patients (see ADVERSE REACTIONS).. Geriatric use. The natural decrement of glomerular filtration with increasing age may lead to elevated vancomycin serum concentrations if dosage is not adjusted. Vancomycin dosage schedules should be adjusted in elderly patients (see DOSAGE AND ADMINISTRATION).. Information for Patients. Patients should be counseled that antibacterial drugs including vancomycin, should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). When vancomycin is prescribed to treat bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed. Skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by vancomycin or other antibacterial drugs in the future.Diarrhea is common problem caused by antibiotics which usually ends when the antibiotic is discontinued. Sometimes after starting treatment with antibiotics, patients can develop watery and bloody stools (with or without stomach cramps and fever) even as late as two or more months after having taken the last dose of the antibiotic. If this occurs, patients should contact their physician as soon as possible.

WARNINGS SECTION.

WARNINGS. Rapid bolus administration (e.g., over several minutes) may be associated with exaggerated hypotension, including shock, and rarely, cardiac arrest. Vancomycin should be administered over period of not less than 60 minutes to avoid rapid-infusion-related reactions. Stopping the infusion usually results in prompt cessation of these reactions.Ototoxicity has occurred in patients receiving vancomycin. It may be transient or permanent. It has been reported mostly in patients who have been given excessive doses, who have an underlying hearing loss, or who are receiving concomitant therapy with another ototoxic agent, such as an aminoglycoside. Vancomycin should be used with caution in patients with renal insufficiency because the risk of toxicity is appreciably increased by high, prolonged blood concentrations.Dosage of vancomycin must be adjusted for patients with renal dysfunction (see PRECAUTIONS and DOSAGE AND ADMINISTRATION).Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including Sterile Vancomycin Hydrochloride, USP and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile.C. difficile produces toxins and which contribute to the development of CDAD. Hypertoxin producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibiotic use. Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents.If CDAD is suspected or confirmed, ongoing antibiotic use not directed against C. difficile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile, and surgical evaluation should be instituted as clinically indicated.