Pharmacokinetics of Ethionamide and Ethionamide Sulfoxide in Patients Established on Treatment for Tuberculosis.

To determine the pharmacokinetics of ethionamide (Eto) and ethionamide-sulfoxide (Eto-SO) in participants with tuberculosis (TB) when Eto is dosed under programmatic conditions.

A single-centre, open-label, exploratory pharmacokinetic study. This study is designed to collect blood samples from participants established on a TB treatment regimen which includes Eto. These samples will be analysed for concentrations of Eto and its metabolite Eto-SO.

The medication will not be provided by the study, participants will receive their standard of care medication from their local clinic. Participants will continue to take their total daily dose of Eto on study as prescribed by their primary caregiver, this will not change for their participation on study.