azithromycin + trimethoprim + sulfamethoxazole

Azithromycin + trimethoprim + sulfamethoxazole is a combination of three antibiotics used together in certain clinical scenarios, notably for the treatment of ocular toxoplasmosis. Azithromycin is a macrolide antibiotic that inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit. Trimethoprim and sulfamethoxazole are commonly co-formulated as a fixed-dose combination (often called co-trimoxazole or TMP-SMX), where they act synergistically to inhibit sequential steps in bacterial folate synthesis—sulfamethoxazole inhibits dihydropteroate synthase, while trimethoprim inhibits dihydrofolate reductase. This triple combination has been studied as an alternative regimen for infections such as ocular toxoplasmosis, showing efficacy and safety in retrospective studies[6][8]. Each component targets different aspects of microbial metabolism or protein synthesis, broadening the antimicrobial spectrum and potentially reducing resistance development.

Brand names

ZithromaxBactrimSeptra

Other names

Azithromycin/TMPSAzithromycin/TMP-SMXAzithromycinTrimethoprim-Sulfamethoxazole