Ethinylestradiol Metronidazole

METRONIDAZOLE OESTROGENS Reports of 1 contraceptive effect Possibly alteration of the bacterial flora necessary for recycling ethinylestradiol from the large bowel, although not certain in every case Advise patients to use additional contraception for the period of antibiotic intake and for 1 month after stopping the antibiotic... 

In 10 women taking a combined oral contraceptive metronidazole 400 mg three times daily for 6 to 8 days had no effect on the AUC of ethinylestra-diol and norethisterone. However, 2 of the 10 women had a rise in plasma progesterone levels suggesting that ovulation may have oeeuned. One of a further 15 women taking metronidazole and a combined oral contraceptive also appeared to ovulate. Of the 3 women who ovulated one also ovulated during a cycle while not taking metronidazole. Another similar study in 10 women found that none ovulated while taking metronidazole and a combined oral contraceptive (ethinylestradiol/norethisterone). ... 

Keep in mind not all antineoplastics belong to hazard categories 4 or 5 (see Sect. 26.3.3), and the other way round some other active substances (such as ethinylestradiol, lithium carbonate, ciclosporin, coal tar, metronidazole and tacrolimus) belong to class 4 or 5. 

---

See also in sourсe #XX -- [ ]

---