To study if an H2-receptor antagonist,
nizatidine, and its metabolites [N-2-monodesmethylnizatidine (N-2-MDMN) and
nizatidine sulfoxide (
nizatidine S-Ox)] would be removed by an
arteriovenous hemofiltration, the authors measured their plasma concentrations and amounts recovered in ultrafiltrate during 11 sessions of an intermittent
hemofiltration performed in seven patients with
renal failure who were given an
oral administration of
nizatidine (150 mg). The concentrations of the parent
drug and its metabolites in plasma and ultrafiltrate were determined with a high-performance liquid chromatography with ultraviolet absorbance detection. The mean (+/- standard deviation [SD]) amounts of
nizatidine removed by the procedure performed at the mean ultrafiltration rate of 18 (range, 11-25) mL/min over the mean duration of 179 (60 to 300) minutes accounted for 1.9 +/- 1.4% of the dose administered. The corresponding values for
N-2-MDMN and
nizatidine S-Ox were 0.3 +/- 0.2% and 0.2 +/- 0.2% of the molar dose of
nizatidine, respectively. There was a significant correlation between the filtration rate and the
hemofiltration clearance of
nizatidine (r = .94, P < .001) or its active metabolite,
N-2-MDMN (r = 0.83, P < .01), indicating that the sieving coefficient (Sc), an index of filtration efficiency, for these compounds is largely constant (0.59 and 0.67 for
nizatidine and N-2-MDMN, respectively) under the current
hemofiltration conditions.(ABSTRACT TRUNCATED AT 250 WORDS)