Can diabetes mellitus modify the plasma concentrations of rifampicin in patients under treatment for tuberculosis?

Effect of Metformin on Plasma Exposure of Rifampicin, Isoniazid, and Pyrazinamide in Patients on Treatment for Pulmonary Tuberculosis

BACKGROUND

To evaluate the effect of metformin on the plasma levels of rifampicin, isoniazid, and pyrazinamide in patients with drug-sensitive pulmonary tuberculosis being treated with first-line antituberculosis treatment (ATT) and to assess the influence of gene polymorphisms on the metabolic pathway of metformin and plasma levels of antitubercular drugs.

METHODS

Nondiabetic adults aged 18-60 years with pulmonary tuberculosis were randomized to either the standard ATT (ATT group) or ATT plus metformin (METRIF group) groups in a phase IIB clinical trial. An intensive pharmacokinetic study with blood collection at 0 hour (predosing), followed by 1, 2, 4, 6, 8, and 12 hours after dosing was conducted during the first month of treatment in a subset of 60 study participants after a minimum of 14 doses. Plasma concentrations of rifampicin, isoniazid, pyrazinamide, and metformin were measured by high-performance liquid chromatography using validated methods, and pharmacokinetic parameters and OCT1 and MATE1 gene polymorphisms were compared between the groups.

RESULTS

Significant increases in the clearance of rifampicin, isoniazid, and pyrazinamide were observed in patients in the METRIF group (n = 29) compared with those in the ATT group (n = 31). The AA genotypes of the single-nucleotide polymorphism of rs2289669 ( MATE1 ) in the METRIF group showed a significantly decreased area under the concentration-time curve to the last observation point and increased clearance of rifampicin.

CONCLUSIONS

Metformin altered rifampicin and isoniazid plasma concentrations in patients receiving antituberculosis treatment for pulmonary tuberculosis with little effect on sputum conversion at the end of treatment. Studies with larger sample sizes are needed to understand host drug-drug interactions.

Diabetes and tuberculosis syndemic in India: A narrative review of facts, gaps in care and challenges

Both diabetes mellitus (DM) and tuberculosis (TB) are prevalent all across in India. TB-DM comorbidity has emerged as a syndemic and needs more attention in India considering gaps in screening, clinical care, and research. This paper is intended to review published literature on TB and DM in India to understand the burden of the dual epidemic and its trajectory and to obtain perspectives on the gaps, constraints, and challenges in care and treatment of this dual epidemic. A literature search was carried out on PubMed, Scopus, and Google Scholar, using the key words 'Tuberculosis' OR 'TB' AND 'Diabetes' OR 'Diabetes Mellitus' AND 'India', focusing on the research published between the year 2000 to 2022. The prevalence of DM is high in patients with TB. Quantitative data on the epidemiological situation of TB/DM in India such as incidence, prevalence, mortality, and management are lacking. During the last 2 years convergence of TB-DM syndemic with the COVID-19 pandemic has increased cases with uncontrolled DM but also made coordinated control of TB-DM operationally difficult and of low effectiveness. Research regarding TB-DM comorbidity is required in the context of epidemiology and management. Detection and bidirectional screening are aggressively warranted. Management of DM in those with TB-DM comorbidity needs more efforts, including training and supervision of frontline workers.