Challenging the management of drug-resistant tuberculosis

The management of multidrug-resistant tuberculosis is notoriously difficult. Christoph Lange and colleagues¹ rightly mention that therapeutic drug monitoring can guide optimal personalised care. However, since the first recommendation for therapeutic drug monitoring in multidrug-resistant tuberculosis two decades ago,² and despite strong evidence that suboptimal drug exposure is a key contributor to drug resistance amplification, little has changed.

Therapeutic drug monitoring is an important tool to help clinicians make informed decisions about optimal dosing. This approach is particularly beneficial during altered drug exposure due to malabsorption (eg, HIV), diabetes, or renal dialysis, in patients with drug–drug interactions or an unexplained, poor treatment response,³ or for drugs with considerable pharmacokinetic variability or narrow toxicity profiles, or both, such as fluoroquinolones, linezolid, and aminoglycosides.⁴