Etonogestrel-releasing contraceptive implant in a patient using thalidomide for the treatment of erythema nodosum leprosum: a case report.

Thalidomide is an immunomodulatory drug and first choice in the treatment of erythema nodosum leprosum. Given its teratogenic potential, it is essential that an effective contraceptive method is used, especially a long-acting reversible contraceptive (LARC) method. The subdermal etonogestrel (ENG)-releasing implant is an adequate method due to the high effectiveness and long-term use. However, interaction between thalidomide and ENG has not been well documented. Concern arises because thalidomide interacts with cytochrome P450 (CYP450) enzymes that metabolize sexual steroids. AIM: We aimed to study the effectiveness and safety of the ENG-implant in a thalidomide user. Case report of a sexually active 21-year-old patient with both Hansen's disease and leprosy reaction type 2 treated with thalidomide requiring effective contraception. Follow-up was up to 36 months after implant placement. Contraception with ENG-implant was effective and safe, based on clinical parameters (reduction of menstrual flow and cervical mucus thickening) and laboratory parameters (gonadotropins and sexual steroids). To the best of our knowledge, this is the first case reported which presents a patient in simultaneous use of thalidomide and ENG-implant. Although this case report preliminary supports effectiveness and safety of ENG-implant as a contraceptive option in women using thalidomide, rigorous drug-drug interaction research is needed to better characterize the interaction between thalidomide and the ENG-implant.