A pharmacokinetic profile of nizatidine in man.

In this report, the pharmacokinetic, pharmacodynamic, and hormonal effects of nizatidine are reviewed in healthy volunteers and in patients with renal or hepatic impairment. The absolute oral bioavailability of nizatidine exceeded 90%; the half-life (t1/2), plasma clearance (Clp), and volume of distribution (Vd) of iv nizatidine were 1.3 h, 461/h, and 1.21/kg, respectively. Within 16 h of dosing volunteers with nizatidine, more than 90% of the administered dose was recovered in urine as parent drug and metabolites; unchanged nizatidine accounted for 65 and 75% of the recovered substances, after oral and intravenous administration, respectively. Renal impairment decreased the elimination of nizatidine and dosage reductions are recommended for patients with creatinine clearance (Clcr) less than 50 ml/min/m2. Nizatidine suppressed gastric acid secretion produced by sham meals, protein meals, or pentagastrin; its antisecretory activity was dose and concentration dependent. Nizatidine was three times more potent than cimetidine. Nizatidine, after oral or iv administration, did not alter hormone concentrations in plasma.