The wide variability of perospirone metabolism and the effect of perospirone on prolactin in psychiatric patients

BackgroundPerospirone was developed in Japan and is used for the treatment of schizophrenia and related illnesses. The authors investigated the relationship between the dosage of perospirone and the plasma levels of perospirone and its active metabolite, ID15036, and also evaluated the impact of the plasma concentrations of perospirone and ID15036 on the plasma prolactin level to examine whether perospirone or ID15036 affected the dopamine D2 blockade, in psychiatric patients treated with perospirone.MethodsThe subjects consisted of 21 adults treated with perospirone (4–60 mg/day). The plasma perospirone and ID15036 levels were measured in 21 patients and serum prolactin levels were investigated in 10 male patients with schizophrenia.ResultsThe plasma ID15036 level was higher than the plasma perospirone, and a positive correlation was observed between the dosage of perospirone and the ID15036 levels (p = 0.032). The 10 male patients showed a positive correlation between the plasma perospirone levels and plasma prolactin levels (r = 0.688, p = 0.028) and between the plasma ID15036 levels and prolactin levels (r = 0.775, p = 0.009).ConclusionThe plasma levels of ID15036 may have a greater impact on the dopamine D2 blockade than perospirone in patients treated with perospirone.