Treatment of premenstrual syndrome with gonadotropin-releasing hormone agonist in a low dose regimen

BACKGROUND: GnRH agonists constitute a well-documented treatment for premenstrual syndrome (PMS). However, the hypo-estrogenic state induced by the treatment renders it less suitable for long-term clinical use. The aim of the current study was to investigate the efficacy of a low dose GnRH agonist with respect to its ability to relieve premenstrual symptoms and maintain regular ovulatory cycles. METHODS: The effect of a low dose GnRH agonist (buserelin) on luteal phase symptomatology was evaluated in 27 women with severe premenstrual syndrome. The design was doubleblind, placebo-controlled and cross-over. Patients were randomized to either GnRH-agonist intranasally in a dosage of 100 microg once daily for two months or placebo for two months before the cross-over was made. The primary outcome measure consisted of daily symptom ratings for mood and physical symptoms made by the patients throughout the study. Adverse events and hormone concentrations were assessed at visits every second week. RESULTS: Premenstrual irritability and depression were significantly relieved by low dose GnRH agonist. Positive symptoms such as friendliness and cheerfulness were also improved during the premenstrual week. Likewise physical symptoms of swelling and headache displayed a significant improvement during buserelin treatment, whereas breast tenderness scores were unaffected by the treatment. The low dose GnRH agonist treatment regimen induced anovulation in as much as 56% of patients, but these subjects were significantly older than those women who maintained ovulatory cycles throughout the study. CONCLUSION: GnRH treatment significantly reduced premenstrual depression and irritability. However, low dose GnRH therapy is prone to induce anovulation, particularly with increasing age.