CLINICAL PHARMACOLOGY SECTION.

CLINICAL PHARMACOLOGY. The exact mechanism by which Pentagastrin stimulates gastric acid, pepsin, and intrinsic factor secretion is unknown; however, since Pentagastrin is an analogue of natural gastrin, it is believed that it excites the oxyntic cells of the stomach to secrete to their maximum capacity. Pentagastrin stimulates pancreatic secretion, especially when administered in large intramuscular doses. Pentagastrin also increases gastrointestinal motility by direct effect on the intestinal smooth muscle. However, it delays gastric emptying time probably by stimulation of terminal antral contractions, which enhance retropulsion.OTHER ACTIONS/EFFECTS Pentagastrin increases blood flow in the gastric mucosa, inhibits absorption of water and electrolytes from the ileum, and promotes sodium and chloride diuresis. It causes contraction of the smooth muscle of the lower esophageal sphincter when administered intravenously. Pentagastrin produces an increase in the motor activity of the colon and rectumONSET OF ACTION 10 minutesTIME TO PEAK EFFECT 20 to 30 minutesDURATION OF ACTION 60 to 80 minutes.

DESCRIPTION SECTION.

DESCRIPTION. Pentagastrin, diagnostic aid, is supplied as sterile solution (1.1 ml/5 ml vial) containing:250 micrograms Pentagastrin per ml0.8 mg Methylparaben and 0.2 mg Propylparaben per mL0.9 mg sodium chloride per mLpH 8. 250 micrograms Pentagastrin per ml. 0.8 mg Methylparaben and 0.2 mg Propylparaben per mL. 0.9 mg sodium chloride per mL. pH 8.

DOSAGE & ADMINISTRATION SECTION.

DOSAGE AND ADMINISTRATION. The intravenous infusion dose has ranged from 0.1 to 12 mcg (0.0001 to 0.012 mg) per kg of body weight per hour administered in 0.9% sodium chloride injection. It can also be used as subcutaneous injection for gastric function study with dose of mcg (0.006 mg) per kg of body weight.

INDICATIONS & USAGE SECTION.

INDICATIONS AND USAGE. Anacidity (diagnosis)--Pentagastrin is indicated as diagnostic aid for evaluation of gastric acid secretory function. It is effective in testing for anacidity (achlorhydria) in patients with suspected pernicious anemia, atrophic gastritis, or gastric carcinoma. It is also effective in determining the reduction in acid output after operations for peptic ulcer, such as vagotomy or gastric resection.Hypersecretory conditions, gastric (diagnosis)--Pentagastrin is indicated as diagnostic aid in testing for gastric hypersecretion in patients with suspected duodenal ulcer or postoperative stomal ulcer, and for the diagnosis of Zollinger-Ellison tumor. Anacidity (diagnosis)--Pentagastrin is indicated as diagnostic aid for evaluation of gastric acid secretory function. It is effective in testing for anacidity (achlorhydria) in patients with suspected pernicious anemia, atrophic gastritis, or gastric carcinoma. It is also effective in determining the reduction in acid output after operations for peptic ulcer, such as vagotomy or gastric resection.. Hypersecretory conditions, gastric (diagnosis)--Pentagastrin is indicated as diagnostic aid in testing for gastric hypersecretion in patients with suspected duodenal ulcer or postoperative stomal ulcer, and for the diagnosis of Zollinger-Ellison tumor.

SPL UNCLASSIFIED SECTION.

INTERACTIONS. The following may affect pentagastrins action:Antacids, anticholinergics, histamine H2-receptor antagosnists, or omeprazoleAcute, obstructing, penetrating or bleeding peptic ulcers. Antacids, anticholinergics, histamine H2-receptor antagosnists, or omeprazole. Acute, obstructing, penetrating or bleeding peptic ulcers. Storage and Handling. Keep refrigerated between 2o and 8oC. Protect from light.