The BLAST- 1 Trial - Cephalexin+Amoxicillin-clavulanate for Tuberculosis

The goal of this randomized controlled trial is to study the early bactericidal activity in adult patients with smear-positive pulmonary tuberculosis. The main question it aims to answer are if cephalexin, in combination with amoxicillin-clavulanate, is effective in the treatment of tuberculosis. Participants with smear-positive tuberculosis will be randomized to either of two groups: Intervention group: cephalexin and amoxicillin-clavulanate. Control group: Standard of care TB treatment. The study period is 2 weeks and participants will be asked to submit multiple sputum samples to measure the bacterial sputum load. They will also submit saliva samples for estimation of drug concentrations in the body. Researchers will compare the intervention group with the control group to see if the trial drugs result in a reduced bacterial sputum load Overall aim: To study the early bactericidal activity of cephalexin, in combination with amoxicillin-clavulanate, in comparison to standard treatment in patients with active pulmonary tuberculosis during the first 2 weeks of treatment. Primary aim: 1. To evaluate the early bactericidal activity (measured as 'time to culture positivity') of cephalexin-clavulanate in comparison, to standard TB treatment (rifampicin, isoniazid, pyrazinamide, and ethambutol). Secondary aim: 2. To asses safety and tolerability of cephalexin together with amoxicillin-clavulanate. 3. To determine key pharmacokinetic (PK) parameters of cephalexin, especially half-life and drug exposure (maximal concentration; Cmax and area under the concentration versus time curve, AUC).