Study of pharmacokinetics and pharmacodynamics of two preparations of metoclopramide.

A pharmacokinetic-pharmacodynamic cross-over study in a group of volunteers (8 male, 4 female) was performed to evaluate the activity and plasma levels of a new sustained-release metoclopramide (CAS 364-62-5) formulation (Cronoprimperan) in comparison to a standard formulation (Primperan). During the course of this trial volunteers on both medications complained of mild to moderate adverse effects as headaches and drowsiness. Elevated monocyte counts were seen in all volunteers at the end of the study without determinable relationship to the medications. No relevant differences were observed between the two preparations in the standard motor and coordination tests. The new sustained-release metoclopramide formulation showed 12-h coverage with a plateau shaped form for achieving constant blood levels throughout the day without reaching blood concentrations above clinically tolerable limits.