Contraception and Tuberculosis

Rifampicin and rifabutin are strong inducers of hepatic cytochrome P450 3A4 and lower circulating oestrogen and progestin, making combined pills, progestin-only pills and implants less reliable during treatment and for about 28 days after it. Pregnancy during tuberculosis treatment is hazardous to mother and foetus, and some antituberculosis medicines are teratogenic or hepatotoxic, so contraception should be reliable throughout.

Medicines that matter. Rifampicin and rifabutin (and rifapentine) induce metabolism. Isoniazid, pyrazinamide, ethambutol, streptomycin, fluoroquinolones and bedaquiline do not alter contraceptive levels meaningfully.

Assessment. Type and site of disease (pulmonary, extrapulmonary, pelvic), treatment regimen and expected duration, HIV status and antiretroviral regimen, liver function, pregnancy status and intention, bleeding pattern and the current method.

Pelvic tuberculosis. Known pelvic tuberculosis is a contraindication to starting an intrauterine device, because of the infection and perforation risk.

Pregnancy test. Offer a test before starting therapy and at any missed period; multi-drug therapy has a risk of foetal harm if pregnancy continues.

Eligibility on rifampicin or rifabutin.

Method comparison. Intrauterine devices (except in pelvic disease) and DMPA are first choice. Implants are acceptable with consistent condoms. Pills are avoided unless no alternative exists.

Hormonal contraception does not affect tuberculosis treatment. There is no interaction that weakens the effect of antituberculosis medicines.

Special groups. Women with HIV on efavirenz or boosted protease inhibitors face a double interaction: favour an intrauterine device or DMPA. Adolescents and postpartum women follow the same selection rules.

Regimen lines.

• DMPA 150 mg intramuscularly every 13 weeks, up to 4 weeks late, or 104 mg subcutaneously every 13 weeks, up to 4 weeks late; backup 7 days if started after day 7 of bleeding.

• Copper T 380A, up to 12 years; levonorgestrel 52 mg device, 5 years; insertion with infection screening, no backup.

• Etonogestrel 68 mg rod (3 years) or levonorgestrel two 75 mg rods (5 years or 3 years by system): backup 7 days if inserted after day 7; add condoms throughout rifampicin or rifabutin use and for 28 days after the last dose.

• If a patient on a combined or progestin-only pill must stay on it while on rifampicin, add condoms every time and continue them for 28 days after stopping.

• Emergency contraception: copper T 380A within 5 days is preferred; if oral only, levonorgestrel 3 mg single dose within 120 hours (double the usual dose).

Switching. Starting rifampicin in a pill user: offer DMPA or a device the same day; condoms in the interim. After treatment ends, the pill effect returns over about 4 weeks.

Follow up. Review at each tuberculosis clinic visit, ask about missed bleeding and pregnancy, and review the method at the end of treatment.

Contraceptive failure. Pregnancy on rifampicin with a pill or implant: exclude ectopic pregnancy; refer for antenatal care and specialist review of the treatment regimen.

Hepatotoxicity. If jaundice or acute hepatitis develops on treatment, stop combined pills (category 3 or 4 with acute hepatitis) and use a method that is not hepatically metabolised, such as a copper device.

Bleeding change after starting rifampicin. Spotting on a pill suggests lowered hormone levels; exclude pregnancy, add condoms and switch.

Red flags. Missed bleeding, pelvic pain, jaundice, new neurological symptoms.

Referral and escalation. Refer suspected pregnancy, pelvic tuberculosis, jaundice and any pregnancy exposure to teratogenic regimens.