Fate of emepronium in man in relation to its pharmacological effects

Summary

After oral administration of¹⁴C-labelled emepronium (150 mg) to two subjects, 1.8 and 3.9% of the radioactivity were recovered from the urine within 24 h, of which 50 and 56% respectively, were excreted during the first 6 h. 23 to 35% of the radioactivity in the urine consisted of emepronium metabolites. 25 mg of the cold compound was injected i.m. in 4 subjects; about 31% was excreted in the urine and about 45% in the faeces within 3 days, probably indicating extensive biliary excretion of unaltered drug. The half-life of emepronium in serum ranged from 1.5 to 2.25 h. The near point of accommodation, salivation and heart rate were compared with the serum concentration of emepronium in a randomized cross-over study in 4 subjects. The heart rate was increased significantly at serum concentrations of about 450 ng/ml, and the secretion of saliva was markedly decreased at about 250 ng/ml. The near point was affected only at the highest serum concentrations.