Additional Information

Description

Sulfamethoxazole/Trimethoprim 800 mg/160 mg tablets are a fixed-dose combination antimicrobial used for the treatment of bacterial infections. It contains sulfamethoxazole, a sulfonamide that inhibits bacterial folic acid synthesis, and trimethoprim, a dihydrofolate reductase inhibitor that prevents bacterial replication. This dual mechanism enhances antibacterial efficacy and reduces the likelihood of resistance development.

The combination exerts bactericidal activity by sequentially blocking two steps in the bacterial folate pathway. Sulfamethoxazole competes with para-aminobenzoic acid (PABA), inhibiting dihydropteroate synthase, while trimethoprim inhibits dihydrofolate reductase, preventing tetrahydrofolate formation. This disruption impairs bacterial DNA synthesis, leading to cell death.

Adverse effects include nausea, vomiting, hypersensitivity reactions, hematologic abnormalities, and renal dysfunction. Severe reactions such as Stevens-Johnson syndrome, toxic epidermal necrolysis, and blood dyscrasias may occur in rare cases. Patients should maintain adequate hydration to reduce the risk of crystalluria and renal complications.