Bactrim is used to treat certain types of infections. Find out what the recommended dosages are, how to take the drug, and more. Trimethoprim-sulfamethoxazole (TMP-SMX) (sold as Bactrim,* Septra,* or Cotrim*) is the treatment of choice for cyclosporiasis. TMP 160 mg plus SMX 800 mg (one double strength tablet), orally, twice a day, for 7 – 10 days. Patients infected with HIV may need longer courses of therapy. Dosage for pediatric patients ≥2 months to 18 years. Medscape - Indication-specific dosing for Bactrim, Bactrim DS, Septra, Septra DS, Cotrim, cotrimoxazole, Sulfatrim (trimethoprim, sulfamethoxazole), frequency-based adverse effects. For UTI, the typical Bactrim dosage for adults is either 1 or 2 tablets, depending on the strength. You will take your dose for 10-14 days. The active ingredients in Bactrim are sulfamethoxazole. For uncomplicated urinary tract infections (UTIs), the standard recommended treatment with Bactrim (trimethoprim/sulfamethoxazole) is one double-strength tablet (160 mg trimethoprim/800 mg sulfamethoxazole) taken orally twice daily for 3 days in women, or 7-14 days in men, as recommended by the American College of Physicians 1. Detailed dosage guidelines and administration information for Bactrim (sulfamethoxazole and trimethoprim). Includes dose adjustments, warnings and precautions. How should I use Bactrim? Take Bactrim exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets. Drink plenty of fluids to prevent kidney stones. Antibiotic medicines can cause diarrhea. Adults generally take one double-strength tablet twice daily for most infections. The duration depends on the infection type, often 3 to 14 days. For severe infections, dosing frequency and amount may increase under medical supervision. Calculate trimethoprim-sulfamethoxazole dose for adults and children by weight and indication. Shows TMP and SMX components, formulation amounts for suspension, SS/DS tablets, and IV with dilution guidance. Trimethoprim-sulfamethoxazole (TMP-SMX), also known as co-trimoxazole, is a combination of two antimicrobial agents that act synergistically against a wide variety of bacteria. Although other combinations of sulfonamides are available with trimethoprim, TMP-SMX is by far the most widely used.