“…3 A variety of potent enzyme inducers known to have deleterious effects on hormonal contraceptives include some antiepileptics (carbamazepine, oxcarbazepine, phenytoin, phenobarbital, primidone, topiramate), [16][17][18][19] antibiotics (rifampicin, rifabutin), [20][21][22][23][24] antifungals (griseofulvin), 25 protease inhibitors (amprenavir, atazanavir, nelfinavir, lopinavir, saquinavir, ritonavir), 26 and non-nucleoside reverse transcriptase inhibitors (efavirenz, nevirapine). 27 There have been sporadic reports of Implanon failure due to suspected interaction with concomitantly administered drugs, resulting in intrauterine 10,11,28 or ectopic [29][30][31] pregnancies. Two of these pregnancies were directly associated with concomitant use of rifampicin.…”