The pharmacokinetics of mianserin.

1 The pharmacokinetics of mianserin hydrochloride have been determined in eight normal healthy volunteers, mean age 27, and 14 elderly patients, mean age 76. 2 Mianserin was administered to volunteers by intravenous infusion (0.011 mg/kg/min for 15 min) and, on another occasion, by mouth, in a single dose of 30 mg. Elderly patients received a single oral dose of 40-60 mg. 3 The terminal elimination half-life was significantly prolonged in the elderly. In young subjects it was 9.6 +/- 1.9 (s.d.) h. In the elderly it was 27 +/- 13.1 (s.d.) h. 4 Apparent oral clearance was significantly reduced in the elderly. In young subjects it was 87.1 +/- 32 (s.d.) h. In the elderly, it was 38.1 +/- 14.8 (s.d.) h. 5 These kinetic differences may have an important bearing on the sedative effects of mianserin.