Pharmacokinetics and pharmacodynamics in man of the dopamine antagonist ergot derivative, bromerguride.

The plasma levels and urinary excretion of the dopamine antagonist, bromerguride, were measured by radioimmunoassay in healthy male volunteers given 50 micrograms i.v. and oral doses of 1 and 2 mg. Plasma prolactin was also measured by radioimmunoassay. Following i.v. injection, the concentration of bromerguride declined biphasically, with half-lives of 7 min and 1.2 h. The total clearance was 32 ml X min-1 X kg-1 and the apparent volume of distribution was 3.61/kg. The bioavailability of oral bromerguride was 29% after 1 mg and 25% after 2 mg. The drug was almost totally metabolized and less than 0.05% of the dose was excreted in urine in 24 h after oral administration. Plasma prolactin levels were increased in a dose-dependent manner for about 8 h. Side-effects were minimal, mainly being tiredness and headache in some of the volunteers.