Sulfamethoxazole-Trimethoprim

Information about Sulfamethoxazole-Trimethoprim

Sulfamethoxazole with trimethoprim is a fixed antibiotic combination that is widely used for mild-to-moderate bacterial infections and as prophylaxis against opportunistic infections.

Liver toxicity of Sulfamethoxazole-Trimethoprim

Like other sulfonamide-containing medications, this combination has been linked to rare instances of clinically apparent acute liver injury.

Mechanism of action of Sulfamethoxazole-Trimethoprim

Trimethoprim-sulfamethoxazole (TMP-SMZ) is a combination of a sulfonamide antibiotic and a methoprim. This combination is widely used for therapy of infections due to susceptible bacteria as well as prevention of opportunistic infections with Pneumocystis jiroveci (formerly carinii) in immune deficient individuals. The two agents are synergistic in inhibition of folate synthesis – the sulfamethoxazole (sul" fa meth ox' a zole) inhibiting production of dihydrofolate from para-aminobenzoic acid, and the trimethoprim (trye meth' oh prim) inhibiting the next step in the pathway from dihydrofolate to tetrahydrofolate.

FDA approval information for Sulfamethoxazole-Trimethoprim

TMP-SMZ was approved for use as a combination antibiotic in the United States in 1973 and is still in wide use, more than 8 million prescriptions being filled yearly. TMP-SMZ is recommended for use in adults and children for urinary tract infections, bronchitis, sinusitis and otitis media and for prophylaxis against opportunistic infections due to parasites and pneumocystitis jiroveci.

Dosage and administration for Sulfamethoxazole-Trimethoprim

TMP-SMZ is available in multiple generic and trade formulations in tablets containing 80 or 160 mg of trimethoprim and 200, 400 or 800 mg of sulfamethoxazole. Trade names include Bactrim, Cotrim, Septra and Sulfatrim.

The following are sulfonamide drugs

• Dapsone
• Sulfadiazine
• Sulfadoxine-Pyrimethamine
• Sulfamethoxazole-Trimethoprim
• Sulfasalazine
• Sulfinpyrazone
• Sulfisoxazole

• Dailymed label info on Sulfamethoxazole-Trimethoprim
• FDA Sulfamethoxazole-Trimethoprim