Absolute bioavailability and pharmacokinetics of medifoxamine in healthy humans

Medifoxamine is a new monoamine re-uptake inhibiting antidepressant drug. Twelve volunteers received 100 mg by i.v. infusion over 15 min and 500 mg by mouth fasting. The treatments were given 1 week apart in a randomised cross-over design. Venous blood samples (10 ml) were taken at intervals for 24 h for h.p.l.c. measurement of serum medifoxamine. A biexponential decline of serum medifoxamine concentration was observed after intravenous administration in all subjects and similar terminal elimination half-lives were observed following both routes, indicating that oral absorption is not rate-limiting. The absolute bioavailability of oral medifoxamine was 21%.