rifampicin + metformin

Rifampicin + metformin is a combination of two small molecule drugs used together primarily in patients with comorbid tuberculosis (TB) and type 2 diabetes mellitus. Rifampicin is a first-line antitubercular agent that inhibits bacterial DNA-dependent RNA polymerase, thereby suppressing RNA synthesis in Mycobacterium tuberculosis. Metformin is an oral antihyperglycemic agent from the biguanide class, which lowers blood glucose by decreasing hepatic glucose production, increasing insulin sensitivity, and enhancing peripheral glucose uptake. The combination is not available as a fixed-dose product but may be co-administered in clinical practice for diabetic TB patients. This combination requires careful monitoring due to significant pharmacokinetic interactions; rifampicin can increase plasma exposure to metformin and may also alter its efficacy or side effect profile[2][5][9]. Conversely, metformin may affect the clearance of rifampicin[9]. Both agents have distinct mechanisms—rifampicin as an antimicrobial and metformin as an antidiabetic with additional immunomodulatory effects that could benefit TB outcomes[4][5].