S. Young, M. S. Opsahl, Marc A. Fritz
Apr 1, 1999
Citations
3
Influential Citations
109
Citations
Quality indicators
Journal
Fertility and sterility
Abstract
OBJECTIVE To determine the serum concentrations of enclomiphene and zuclomiphene across consecutive cycles of clomiphene citrate treatment in anovulatory infertile women. DESIGN Prospective cohort. SETTING Tertiary institutional infertility clinic. PATIENT(S) Fourteen consenting anovulatory infertile women receiving standardized, cyclic, incremental treatment with clomiphene citrate for ovulation induction. INTERVENTION(S) Clomiphene citrate treatment (50-150 mg/d, cycle days 5-9), titrated to the minimum effective ovulation-inducing dose, was administered for three to six total cycles. Blood samples were obtained on cycle days 3 and 10 in each treatment cycle. MAIN OUTCOME MEASURE(S) Serum concentrations of enclomiphene and zuclomiphene. RESULT(S) Cycle day 3 zuclomiphene levels were below assay limits in all initial cycles, increased progressively across three consecutive cycles, and thereafter plateaued. Cycle day 3 enclomiphene concentrations were uniformly undetectable. Cycle day 10 enclomiphene levels increased with dose administered, but these observations were not statistically significant. CONCLUSION(S) Clomiphene citrate induction of ovulation results in an isomer-specific systemic accumulation of zuclomiphene across consecutive cycles of treatment. The combined maximum concentration of enclomiphene and zuclomiphene attained in practice approximates 100 nmol/L and is generally well below levels previously demonstrated to have adverse effects in vitro.