Plasma concentrations of clomipramine and desmethylclomipramine in obsessive-compulsive neurosis

Patients suffering from chronic obsessive-compulsive states were treated with clomipramine up to 200 mg/day according to tolerance for periods up to 8 months and their plasma clomipramine and desmethylclomipramine concentrations determined weekly by a double radioisotope derivative technique. Plasma concentrations of both the parent compound and its metabolite rose with dose and within 7-14 days of constant dosage reached steady states. A strong positive correlation was found between clomipramine, and to a lesser extent desmethylclomipramine, and the daily dose of clomipramine. In almost all patients plasma desmethylclomipramine concentrations exceeded those of unchanged drug by a factor of two or three.