To assess efficacy of fluoxetine, 60 mg per menstrual cycle, in the treatment premenstrual dysphoric disorder (PMDD).

114 female outpatients aged between 18 and 45 years old, who met DSM-IV-TR criteria for PMDD, were randomly assigned to receive either fluoxetine or amitriptyline during luteal phase for 4 menstrual cycles. Fluoxetine was administered in 3 doses according to the following scheme: 20 mg/day for 2 consecutive days starting from the beginning of luteal phase and 20 mg/day after 7 days since first dose. Amitriptyline was administered in dose of 25 mg/day continuously during the whole luteal phase. Efficacy measures included HAMD17 total score, individual HAMD17 items, HAMA total score, individual HAMA items, CGI-S and CGI-I scales.

Compared with amitriptyline, 60 mg of fluoxetine per menstrual cycle produced significantly greater baseline-to-endpoint mean change in HAMD17 total score, and items 8 (Retardation), and 13 (Somatic symptoms general) as well; HAMA total score, and items 5 (Intellectual), 8 (Somatic symptoms – Sensory), and 9 (Cardiovascular symptoms) as well; and the CGI-I scale (LOCF analyses; p<.01 for each variable). 50%-reduction from baseline of HAMD17 total score, as well as HAMA total score was observed at the end of 1 course of therapy (end of 1 luteal phase) in both treatment groups. There was no significant difference in CGI-S scale baseline-to-endpoint mean change between fluoxetine and amitriptyline groups.

60 mg of fluoxetine per menstrual cycle demonstrated comparative or superior efficacy as compared with amitriptyline in standard dose in the treatment of PMDD.