Does meloxicam increase the incidence of anovulation induced by single administration of levonorgestrel in emergency contraception? A pilot study

M. R. Massai, M. L. Forcelledo, V. Brache, A. S. Tejada, A. M. Salvatierra, M. V. Reyes, F. Alvarez, A. Faúndes, H. B. Croxatto

Research output: Contribution to journalArticlepeer-review

48 Citations (Scopus)

Abstract

Backgroud: Levonorgestrel (LNG) consistently prevents follicular rupture only when it is given before the onset of the ovulatory stimulus. As locally synthesized prostaglandin (PG) plays a crucial role in follicular rupture and cyclooxygenase-2 (cox-2) catalyses the final step of PG synthesis, we reasoned that adding a cox-2 inhibitor to LNG would prevent follicular rupture even after the ovulatory process had been triggered by the gonadotrophin surge. Methods: Forty-one women were divided into two groups. One was treated when the size of the leading follicle was 15-17 mm (n = 10) and the other when it was ≥18 mm (n = 31). Each woman contributed with one cycle treated with LNG 1.5 mg single dose plus placebo and another treated with LNG + meloxicam (Melox) 15 mg, in a randomized order. Serial blood sampling for the assay of LH and follicular monitoring by transvaginal ultrasound were performed before and after treatment. Results: Follicular rupture failed to occur within the 5-day period that followed treatment in 50 and 70% of cycles treated with LNG + Placebo and LNG + Melox, respectively, in the 15-17 mm group (P = 0.15) and in 16 and 39% of cycles treated with LNG + Placebo and LNG + Melox, respectively, in the ≥18 mm group (P < 0.052). The overall proportion of cycles with no follicular rupture or ovulatory dysfunction increased significantly by the addition of Melox to LNG (66 versus 88%, P < 0.012; n = 41-matched pairs). Conclusions: The trend towards increased incidence of no follicular rupture when Melox was combined with LNG suggests that the addition of a cox-2 inhibitor has the potential to improve the contraceptive efficacy of LNG by a pre-fertilization effect.

Original languageEnglish
Pages (from-to)434-439
Number of pages6
JournalHuman Reproduction
Volume22
Issue number2
DOIs
Publication statusPublished - Feb 2007

Keywords

  • Cyclooxygenase-2 inhibitor
  • Emergency contraception
  • Levonorgestrel
  • Meloxicam
  • Ovulation

ASJC Scopus subject areas

  • Reproductive Medicine
  • Obstetrics and Gynaecology

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