The Effect of Diabetes Mellitus on the Pharmacokinetics of Tuberculosis Drugs

While pharmacokinetics (PK) of many drugs is known to be altered in individuals with diabetes mellitus (DM), the effects of DM on the PK of anti-tuberculosis (TB) drugs remains poorly understood. We performed a systematic review through searches of major databases from 1946 to 6 July 2023. The literature search identified 4173 potentially relevant articles. After reviewing the eligibility criteria, 21 articles were included that assessed the PK of anti-TB drugs among patients with DM. Most articles focused on first line TB drugs; we identified 16 studies assessing rifampicin PK, 9 studies on isoniazid, 8 on pyrazinamide and 3 assessing ethambutol. Only 2 studies reported on second line anti-TB treatment. While some studies showed lower plasma concentrations of TB medications among DM patients, this finding was not consistent. In addition, we observed high variability in findings and significant heterogeneity among studies in terms of study design and differences in demographics. This review provides detailed overview of the limited evidence available regarding the PK of anti-TB medications in patients with DM. However, due to significant heterogeneity between studies, no conclusions could be made. Adequately designed PK studies using standardise methodologies are urgently needed to make recommendations regarding drug dosing in patients affected both by TB and DM.