PHARMACOKINETICS OF METOCLOPRAMIDE AFTER INTRAARTERIAL, INTRAMUSCULAR, SUBCUTANEOUS, AND PERRECTAL ADMINISTRATION IN RABBITS

The objective of this investigation was to compare the pharmacokinetics of metoclopramide (MET) after intraarterial (IA), intramuscular (IM), subcutaneous (SC), and perrectal (PR) administrations to normal rabbits. In this study, 6 normal New Zealand white rabbits were used in a random crossover design (4 4 Latin square) with a 1-week washout period between trials. Each rabbit had been administered MET at a dose of 2 mg/kg IA, IM, and SC, and 4 mg/kg PR. The plasma concentrations of MET were determined by high-performance liquid chromatography. The mean plasma profiles of MET after IA, IM, and SC administrations were similar. The bioavailability of MET when administered IM and SC was 96% and 112%, respectively. The plasma concentrations within the PR group were quite variable, resulting in an extremely low and variable bioavailability with an average of 12%. IM and SC administrations of MET may be useful in treating gastrointestinal disorders in rabbits when arterial or venous access is not available, but PR administration is likely to be unreliable.