The
macrolides clarithromycin,
dirithromycin, roxithromycin and
telithromycin appear unlikely to cause combined hormonal contraceptive failure. Isolated cases of contraceptive failure have been attributed to
erythromycin or spiramycin. Conversely, in two studies of contraceptive failures in dermatology patients, no pregnancies were identified in a total of 74 women taking
erythromycin with oral
contraceptives.
For guidance on the use of antibacterials with
contraceptives, see
contraceptives.