Nimodipine to Prevent LH Surge During Ovulation Induction: Blinded Placebo-controlled RCT

Summary

The main purpose of this study is to test the effectiveness of nimodipine in preventing a luteinizing hormone (LH) surge in women undergoing ovulation induction with clomiphene citrate. It is important to prevent the premature LH surge in controlled ovarian stimulation to allow adequate recruitment of follicles, proper maturation of a dominant follicle before ovulation, and effectively time insemination with semen to allow fertilization of a mature egg to occur. The investigators are also conducting this study to determine medication side effect profile (including lightheadedness or dizziness from low blood pressure or rapid heart rate, headache, and nausea), patient treatment compliance, and clinical pregnancy (positive pregnancy test and ultrasound evidence of fetal heart rate). Finally, LH and follicle stimulating hormone (FSH) serum levels will be measured to determine effect of nimodipine on these hormones. As a calcium channel blocker, nimodipine has been shown to block calcium mediated release of gonadotropin releasing hormone in animal and preliminary human studies. The investigators hypothesize that nimodipine, a calcium channel blocker, will prevent or delay the LH surge during controlled ovarian stimulation cycles using clomiphene citrate in subfertile patients undergoing assisted reproduction with intrauterine insemination (IUI).

Timeline

Start

2012-09

Primary completion

2014-04

Completion

2014-04

Publications

• Background Chen EC, Javors MA, Norris C, Siler-Khodr T, Schenken RS, King TS. Dependence of 3',5'-cyclic adenosine monophosphate--stimulated gonadotropin-releasing hormone release on intracellular calcium levels and L-type calcium channels in superfused GT1-7 neurons. J Soc Gynecol Investig. 2004 Sep;11(6):393-8. doi: 10.1016/j.jsgi.2004.02.010.
• Background Krsmanovic LZ, Stojilkovic SS, Merelli F, Dufour SM, Virmani MA, Catt KJ. Calcium signaling and episodic secretion of gonadotropin-releasing hormone in hypothalamic neurons. Proc Natl Acad Sci U S A. 1992 Sep 15;89(18):8462-6. doi: 10.1073/pnas.89.18.8462.
• Background Nunez L, Villalobos C, Boockfor FR, Frawley LS. The relationship between pulsatile secretion and calcium dynamics in single, living gonadotropin-releasing hormone neurons. Endocrinology. 2000 Jun;141(6):2012-7. doi: 10.1210/endo.141.6.7491.

Drugs

Indications