Brands, Medical Use, Clinical Data
Drug Category
- Anti-ulcer Agents
- Histamine H2 Antagonists
Dosage Forms
Brands / Synonyms
Acinon; Antizid; Axid; Axid Ar; Calmaxid; Cronizat; Distaxid; Galitidin; Gastrax; Naxidine; Niatidine; Nizatidina [Spanish]; Nizatidine [Usan:Ban:Inn:Jan]; Nizatidinum [Latin]; Nizax; Nizaxid; Panaxid; Splendil Er; Tazac; Ulcosol; Ulxid; Zanizal; Zinga
Indications
For the treatment of acid-reflux disorders (GERD), peptic ulcer disease, active benign gastric ulcer, and active duodenal ulcer.
Pharmacology
Nizatidine is a competitive, reversible inhibitor of histamine at the histamine H2-receptors, particularly those in the gastric parietal cells. By inhibiting the action of histamine on stomach cells, nizatidine reduces stomach acid production. Nizatidine had no demonstrable antiandrogenic action. Full-dose therapy for the problems treated by nizatidine lasts no longer than 8 weeks. It has been demonstrated that treatment with a reduced dose of nizatidine is effective as maintenance therapy following healing of active duodenal ulcers.
Mechanism of Action
Nizatidine competes with histamine for binding at the H2-receptors on the gastric basolateral membrane of parietal cells. Competitive inhibition results in reduction of basal and nocturnal gastric acid secretions. The drug also decreases the gastric acid response to stimuli such as food, caffeine, insulin, betazole, or pentagastrin.
Absorption
Rapid (bioavailability of nizatidine exceeds 70%)
Toxicity
Oral, rat LD50: 301 mg/kg. Symptoms of overdose include cholinergic-type effects including lacrimation, salivation, emesis, miosis, and diarrhea.
Biotrnasformation / Drug Metabolism
Hepatic. Less than 7% of an oral dose is metabolized as N2-monodes-methylnizatidine, an H2-receptor antagonist, which is the principal metabolite excreted in the urine. Other likely metabolites are the N2-oxide (less than 5% of the dose) and the S-oxide (less than 6% of the dose).
Contraindications
Nizatidine is contraindicated in patients with known hypersensitivity to the drug. Because cross sensitivity in
this class of compounds has been observed, H2-receptor antagonists, including nizatidine, should not be
administered to patients with a history of hypersensitivity to other H2-receptor antagonists.
Drug Interactions
No interactions have been observed between nizatidine and theophylline, chlordiazepoxide, lorazepam, lidocaine,
phenytoin, and warfarin. Nizatidine does not inhibit the cytochrome P-450-linked drug-metabolizing enzyme system;
therefore, drug interactions mediated by inhibition of hepatic metabolism are not expected to occur. In patients
given very high doses (3900 mg) of aspirin daily, increases in serum salicylate levels were seen when nizatidine, 150
mg b.i.d., was administered concurrently.
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