Serum mianserin concentrations in psychiatric inpatients of different ages.

One hundred and sixty-nine depressive psychiatric inpatients were treated with routine therapeutic doses of mianserin. Altogether 256 serum mianserin samples were measured gas-chromatographically in 3 age groups: 17 samples in patients under 35 years, 116 samples in patients between 35 and 65 years, and 123 samples in patients over 65 years. No differences in dose-corrected (calculated as mg/kg dose basis) mean serum mianserin concentrations were found between the age classes. Neither the interindividual variation nor the number of high serum mianserin concentrations was larger among elderly subjects than in the other age groups. Concurrent neuroleptic treatment significantly increased serum mianserin levels in the oldest patient group but not in the 2 others. The results suggest that mianserin dose should not be generally reduced with advancing age.