12th January 2024

Management

Adults aged under 65 years old with latent TB are treated with either:

• 3 months of isoniazid (with pyridoxine) and rifampicin or
• 6 months of isoniazid (with pyridoxine).

The risk of hepatotoxicity from these medications has been shown to significantly increase in patients aged over 65 years, and therefore, the decision to treat latent TB infection in elderly patients requires careful consideration of risks and benefits.

Patients with active TB without central nervous system (CNS) involvement should be offered:

• isoniazid (with pyridoxine), rifampicin, pyrazinamide and ethambutol for 2 months then
• isoniazid (with pyridoxine) and rifampicin for a further 4 months.

For patients with CNS involvement, isoniazid (with pyridoxine) and rifampicin are continued for 10 months (rather than four) after the initial two months of quadruple therapy.

Patients with active TB admitted to hospital should be cared for in a single room until they have completed two weeks of the standard treatment regimen. If the patient is suspected or confirmed to have multi-drug resistant TB, whereby the organism is resistant to isoniazid and rifampicin (+/- other anti-tuberculous treatments), the patient should be managed in a negative pressure room.

Adverse effects of TB medications

Patients starting on a TB treatment regime must have their liver and renal function assessed before commencing treatment. Visual acuity should be tested by Snellen chart before treatment with ethambutol.

Table 1: adverse effects of medications used to treat tuberculosis. Adapted from: Antitubercular Medications – StatPearls – NCBI Bookshelf [Internet]. [cited 2022 Mar 11]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK557666/