Nizatidine suppression of basal gastric acid output: a comparison of two intravenous dosage regimens.
To study the pharmacokinetics and pharmacodynamics of two intravenous nizatidine dosing regimens, serial plasma concentrations and continuous intragastric pH were monitored simultaneously in 10 subjects with a documented history of duodenal or gastric ulcers. A 24-hour gastric pH profile was characterized for a 300 mg daily dose of nizatidine randomly administered both as 100 mg every 8 hours and 150 mg every 12 hours. No significant differences were observed in the mean pharmacokinetic parameters between the two dosing regimens. Pharmacodynamic parameters for the 100 mg every 8 hours versus the 150 mg every 12 hours regimen were not significantly different except for percent of time during the 24-hour study period that the pH was maintained greater than 4 (43.6 +/- 20.7 versus 34.7 +/- 18.3, P less than .05). A significant relationship was demonstrated for both regimens (P less than .05) between the percent time pH greater than 4 and area under the plasma curve for the 24 hour study period. The lack of a significant difference in nizatidine pharmacokinetics between the two dosage regimens suggests a pharmacodynamic cause for the greater cumulative pH effect of the every 8 hour regimen.
Danziger
L
L
College of Pharmacy, University of Illinois, Chicago 60612.
Furmaga
K M
KM
Rodvold
K A
KA
Bombeck
C T
CT
Fischer
J H
JH
D000328:Adult; D000368:Aged; D005744:Gastric Acid / Q000378:metabolism*; D005745:Gastric Acidity Determination; D006207:Half-Life; D006635:Histamine H2 Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D007275:Injections, Intravenous; D008875:Middle Aged; D016567:Nizatidine; D011897:Random Allocation; D013844:Thiazoles / Q000008:administration & dosage / Q000494:pharmacology*
D006635:Histamine H2 Antagonists; D013844:Thiazoles; D016567:Nizatidine