Influence of food on the oral bioavailability of moxonidine

Moxonidine is a new centrally acting anti-hypertensive with a very low adverse drug reaction profile. Among others, the aim of the study presented here was to determine the influence of food on the pharmacokinetics of moxonidine. Single oral moxonidine doses of 0.2 mg fasting and 0.2 mg non-fasting were administered in a randomized cross-over study. Eighteen subjects participated in the study, all of whom completed the study according to the protocol. Three sets of analytical plasma data could not be evaluated pharmacokinetically giving a total number of 15 evaluable cases. Renal excretion was evaluated for all 18 subjects. Food intake had no influence on the pharmacokinetics of moxonidine. The relative bioavailability of moxonidine administered under non-fasting conditions reached 94% of the bioavailability after fasted administration. Food intake resulted in a slight decrease of Cmax and a minimal increase of tmax as compared to the fasted treatment. The absorption half-life t1/2a showed a minor prolongation. These differences were not statistically significant in any of the parameters. For t1/2 lambda 2, CLtot and Ae(24h) no statistically significant differences were found between the fasting and non-fasting treatment. The amount of moxonidine excreted unchanged in urine accounted for about 46% of the dose administered after both treatments.