Blood and plasma concentrations of dothiepin and its major metabolites and clinical response.

Ten patients suffering from primary depressive illness were treated with 150 mg/d of dothiepin for 4 weeks. Blood and plasma concentrations of dothiepin and two metabolites, dothiepin S-oxide and northiaden were measured by gas chromatography-mass spectrometry. Severity of depression was assessed using the Hamilton Depression Rating Scale. No significant correlation was found between amelioration score or percentage change and either blood or plasma concentrations of dothiepin, its metabolites or total drug and metabolite concentrations at week 4.