title: Nimodipine, a calcium channel blocker, delays the spontaneous LH surge in women with regular menstrual cycles: a prospective pilot study.
abstract: BACKGROUND
  Currently GnRH analogue injections are used to prevent premature LH surges in women undergoing assisted reproductive technology. This was a pilot study to determine the safety and effectiveness of nimodipine, an oral calcium channel blocker, to delay the mid-cycle spontaneous LH surge in women with regular menstrual cycles.
  
  
  METHODS
  Eight women with regular menstrual cycles self-monitored three consecutive cycles for the day of an LH surge by daily urine assay. The first and third cycles were observatory. In the second cycle, subjects took nimodipine 60 mg by mouth three times daily for four days, starting two days prior to the expected LH surge day based on cycle one.
  
  
  RESULTS
  The LH surge day in cycle 2 (nimodipine) was significantly delayed in comparison to both observatory cycle 1 (15.5+/-3.4 vs 14.0+/-2.8 days; p=0.033) and cycle 3 (15.1+/-3.5 vs 13.1+/-2.4 days; p=0.044). There was no difference in the LH surge day between the two observatory cycles (13.4+/-2.4 vs 13.1+/-2.4 days; p=0.457). Three patients experienced a mild headache.
  
  
  CONCLUSIONS
  There was a statistically significant delay in the spontaneous LH surge day in the treatment cycle in comparison to both observatory cycles. Nimopidine should be further investigated as an oral alternative to delay a spontaneous LH surge.
authors: Department of Obstetrics & Gynaecology, Mount Sinai Hospital, University of Toronto, 92 College Street, Toronto, Canada.
authors: Dan
authors: D
authors: Nayot
authors: Shany
authors: S
authors: Klachook
authors: Robert F
authors: RF
authors: Casper
mesh_terms: D000328:Adult; D002121:Calcium Channel Blockers / Q000008:administration & dosage*; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000502:physiology; D006261:Headache / Q000139:chemically induced; D006801:Humans; D007986:Luteinizing Hormone / Q000187:drug effects* / Q000378:metabolism*; D008597:Menstrual Cycle / Q000187:drug effects; D009553:Nimodipine / Q000008:administration & dosage* / Q000009:adverse effects; D010060:Ovulation / Q000187:drug effects*; D010865:Pilot Projects; D011446:Prospective Studies; D027724:Reproductive Techniques, Assisted
chemical_list: D002121:Calcium Channel Blockers; D007987:Gonadotropin-Releasing Hormone; D009553:Nimodipine; D007986:Luteinizing Hormone
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