A clomiphene citrate and tamoxifen citrate combination therapy: a novel therapy for ovulation induction

To assess the efficacy of a clomiphene citrate (CC) and tamoxifen citrate (CC/tamoxifen) combination therapy in ovulation induction by comparing with a CC alone therapy.

A randomized cross-over study with CC alone and CC/tamoxifen combination therapies for 20 normoprolactinemic anovulatory women. Randomly selected 10 of the 20 women (group A) underwent a CC alone therapy (100 mg CC during cycle days 5 to 9) for the initial three consecutive treatment cycles and a CC/tamoxifen combination therapy (50 mg CC and 20 mg tamoxifen during cycle days 5 to 9) for the subsequent three consecutive treatment cycles. The remaining 10 (group B) were treated similarly but with the inverse sequence. Ovulation was documented when a high BBT phase persisted for 11 days or more, when midluteal serum P levels exceeded 7 ng/mL (22.3 nmol/L), or when pregnancy ensued.

The rates of ovulatory/treated, pregnant/treated, and pregnant/ovulatory cycles were 42 of 56 (75.0%), 3 of 47 (6.4%), and 3 of 35 (8.6%) for CC/tamoxifen, respectively. Those were 25 of 57 (43.9%), 1 of 48 (2.1%), and 1 of 21 (4.8%) for CC, respectively. Clomiphene citrate/tamoxifen was more effective in ovulation induction than CC. All the pregnancies were normal and single. None of the treatments was accompanied by any remarkable side effects.

Clomiphene citrate/tamoxifen is a novel treatment modality of ovulation induction with high efficacy.