Pharmacokinetics of diphemanil methylsulphate in healthy subjects.

The pharmacokinetic parameters of oral diphemanil methylsulphate have been evaluated in six healthy male volunteers. Absorption of the drug was slow (tmax = 2 to 4 h), the mean half-life was 8.35 h, and the amount of the drug recovered in urine within 48 h ranged from 0.6 to 7.4% of the administered dose. The results suggest low bioavailability, assuming that the drug is poorly metabolized.