Rationale: It is well established that serotonin reuptake inhibitors (SRIs) are effective for the treatment of premenstrual dysphoria (PMD), but the receptor subtype(s) mediating this effect of serotonin have yet not been identified.
Objective: In this trial, the possible efficacy of buspirone, a partial 5HT1A receptor agonist, and nefazodone, a combined SRI and 5HT2 receptor antagonist, was evaluated in women with PMD.
Methods: After a three-menstrual-cycle screening phase, patients were randomised to buspirone (n=19), nefazodone (n=22) or placebo (n=22). During the first two treatment cycles, patients were taking the drug during the luteal phase only (mean +/- SD daily dose of buspirone: 21 +/- 6 mg; nefazodone: 228 +/- 54 mg). During the subsequent two cycles, the medication was taken each day of the menstrual cycle (mean daily dose of buspirone: 27 +/- 10 mg; nefazodone: 304 +/- 95 mg).
Results: With respect to self-rated global improvement, buspirone (P<0.001) but not nefazodone was significantly superior to placebo. While buspirone appeared to reduce self-rated irritability (visual analogue scale) more effectively than placebo, other self-rated symptoms did not differ markedly between the groups. The side-effects were mild, and sexual dysfunction was not significantly more common in patients given buspirone or nefazodone than in those given placebo.
Conclusion: It is suggested that buspirone is mildly effective for premenstrual irritability. In patients experiencing sexual dysfunction when treated with an SRI, buspirone may be a useful alternative.