Ectopic pregnancy with Implanon<SUP>®</SUP>

Failure of Implanon&reg; on antituberculous therapy

“…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.…”

“…Two of these pregnancies were directly associated with concomitant use of rifampicin. 10,29 This woman was treated with rifampicin-isoniazid while using Implanon. Etonogestrel is metabolized by the CYP3A4 enzyme system and rifampicin is known to induce and isoniazid to inhibit certain CYP enzyme systems, particularly CYP3A4 and other Phase I and Phase II enzyme systems in the liver.…”

Medicines For Women

“…Additionally, this case series identified that a number of failures occurred as a result of concomitant use of enzyme inducing drugs (Harrison-Woolrych and Hill 2005). Other reports of failures possibly as a consequence of drug interactions are documented (Patni et al 2006;Lakhi and Govind 2010;McCarty et al 2011;Matiluko et al 2007;Haukkamaa 1986;Gbolade 2010): product information warns that efficacy may be reduced with concomitant use of drugs which induce hepatic enzymes, specifically cytochrome P450, for example carbamazepine or rifampacin (Merck Sharp and Dohme Limited 2013). In 2014, the Medicines and Healthcare Regulatory Agency (MHRA) in the UK produced a Drug Safety Update (Medicines and Healthcare Products Regulatory Agency 2014) which highlighted that in the last quarter of 2013 the MHRA had received two reports of unintended pregnancies occurring in women using the etonogestrel implant possibly as a consequence of using St John's Wort.…”

“…A published review of clinical trials and marketing data suggested that ectopic pregnancies accounted for around 5 % of all reported pregnancies whilst using Implanon ® (Graesslin and Korver 2008). Case reports of ectopic pregnancy have also been documented following concomitant use of drugs that may affect the efficacy of progestogen-only implants such as anti-retrovirals (Patni et al 2006;McCarty et al 2011). In the UK, there are 57 ectopic pregnancies on file which could relate to use of the etonogestrel implant (Medicines and Healthcare Products Regulatory Agency 2013).…”

Ectopic pregnancy with Implanon® as a method of contraception in a woman with a previous ectopic pregnancy – Case report

“…Kennedy and Murnaghan 6 History of PID; use of a POP before insertion of the implant -Mansour et al 7 --Patni et al 8 -Rifampicin Mansour 9 --Henderson 10 -Sertraline Current case Previous EP -PID, pelvic inflammatory disease; POP, progestogen-only pill.…”