This pharmacokinetic (PK) study evaluated if a double dose (3.0 mg) of levonorgestrel (LNG) overcomes known drug-drug interactions (DDIs) with efavirenz (EFV)-based antiretroviral therapy (ART) or rifampicin (RIF)-containing tuberculosis (TB) therapy. The safety of double-dose (3.0 mg) LNG versus standard-dose (1.5 mg) was also compared.~Participants were volunteers who did not require emergency contraception (EC) for contraception at the time of trial participation. This trial enrolled persons assigned female sex at birth who were 16 years of age or older. Group assignment was determined by disease status (HIV or TB; participants could not have been living with both HIV and TB), and, for those with HIV, by ART regimen at enrollment. Participants with HIV who were taking EFV-based ART were randomized to receive a standard dose LNG (Group A) or a double dose of LNG (Group B). Participants taking dolutegravir (DTG)-based ART were assigned to a standard dose of LNG (Group C). Participants in the continuation phase of active TB treatment taking RIF and isoniazid (INH) with or without ethambutol were assigned to a double dose of LNG (Group D).~At study entry, participants in Groups A and C received a standard single dose of LNG. Participants in Groups B and D received a double dose of LNG. Intensive PK monitoring was conducted pre-dose, and after the LNG dose. Participants were expected to remain at the clinical site while the initial 8 hour PK samples were collected, and to return to the clinical site for the 24 and 48 hour samples.~All participants completed self-report questionnaires to assess adherence to TB therapy and ART, menstrual history and patterns after LNG administration, and to collect adverse effects commonly reported with LNG (i.e., irregular bleeding patterns). Adherence to ART and RIF was also assessed by collecting hair samples and single plasma concentrations at entry. Participants were followed for 4 weeks.
The purpose of this pharmacokinetic (PK) study was to evaluate if a double dose (3 mg) of levonorgestrel (LNG) overcomes known drug-drug interactions (DDIs) with efavirenz (EFV)-based antiretroviral therapy (ART) or rifampicin (RIF)-containing tuberculosis (TB) therapy. The safety of double-dose (3.0 mg) LNG versus standard-dose (1.5 mg) was also compared.