Risk for ovulation in women taking a low-dose oral contraceptive (Microgynon) when receiving antibacterial treatment with a fluoroquinolone (ofloxacin).
The possibility of escape ovulation in women using a fluoroquinolone ofloxacin for antibacterial treatment at a dose of 200 mg twice daily for 7 days when taking a combined oral contraceptive (Microgynon, 150 micrograms levonorgestrel and 30 micrograms ethinyl estradiol) was studied in 20 women. By using a placebo-controlled, randomized, cross-over design 6 contraceptive pill cycles were followed. Follicle-stimulating hormone and estradiol concentrations were measured on tablet days 5-8, 19-21; progesterone was assayed on days 19-21 during treatment with ofloxacin or placebo. Ultrasonographical investigations for measurements of the number and diameter of ovarian follicles were performed on one of days 5-10, 11-17, 18-24, 25-28. No indications of ovulation during ofloxacin medication were detected. It is concluded that alternative contraceptive precautions should not be needed when ofloxacin is prescribed for patients taking oral contraceptives.
Csemiczky
G
G
Department of Woman and Child Health, Karolinska Hospital, Stockholm, Sweden.
Alvendal
C
C
Landgren
B M
BM
D000328:Adult; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000009:adverse effects*; D015331:Cohort Studies; D003277:Contraceptives, Oral, Combined / Q000494:pharmacology*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004958:Estradiol / Q000097:blood / Q000378:metabolism; D019304:Ethinyl Estradiol-Norgestrel Combination / Q000494:pharmacology*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood / Q000378:metabolism; D006801:Humans; D015242:Ofloxacin / Q000008:administration & dosage / Q000009:adverse effects*; D010060:Ovulation / Q000187:drug effects* / Q000502:physiology; D011374:Progesterone / Q000097:blood / Q000378:metabolism; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors
D000890:Anti-Infective Agents; D003277:Contraceptives, Oral, Combined; D011374:Progesterone; D004958:Estradiol; D019304:Ethinyl Estradiol-Norgestrel Combination; D005640:Follicle Stimulating Hormone; D015242:Ofloxacin