The role of therapeutic drug monitoring in individualised drug dosage and exposure measurement in tuberculosis and HIV co-infection

We read with interest the paper by Esposito et al. [1] reporting a difficult-to-treat extensively drug-resistant tuberculosis (TB) case. TB treatment in HIV-positive individuals can also be particularly challenging. An HIV-positive 26-year-old male showing excessive weight loss (body mass index 17.5 kg·m−2) and clinical deterioration was admitted to the Beatrixoord Tuberculosis Centre (University Medical Center Groningen, Haren, the Netherlands) for the treatment of pulmonary TB. Mycobacterium tuberculosis isolated from sputum appeared susceptible to all first-line drugs tested. The patient received rifampicin (RIF) (600 mg), isoniazid (300 mg), pyrazinamide (1500 mg) and ethambutol (1200 mg) under directly observed therapy. He started with emtricitabine (200 mg), tenofovir (245 mg) and raltegravir (800 mg twice daily) 2 weeks later as combination antiretroviral therapy. Wider use of TDM in complex TB cases could improve therapeutic management and prevent emergence of drug resistance