Drug Groups

approved

Description

A histamine H2 receptor antagonist with low toxicity that inhibits gastric acid secretion. The drug is used for the treatment of duodenal ulcers. [PubChem]

Indication

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.

Toxicity

Oral, rat LD₅₀: 301 mg/kg. Symptoms of overdose include cholinergic-type effects including lacrimation, salivation, emesis, miosis, and diarrhea.

Affected Organisms

Biotransformation

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).

Absorption

Rapid (bioavailability of nizatidine exceeds 70%)

Half Life

1-2 hours

Protein Binding

35%

Distribution

* 0.8 to 1.5 L/kg

Clearance

* 40-60 L/h
* 7 – 14 L/h [functionally anephric patients]

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