Maximum Daily Dosing of Septrin (Trimethoprim-Sulfamethoxazole)

Adult Dosing by Indication

The American College of Physicians and Infectious Diseases Society recommends one to two double-strength tablets twice daily (320-640 mg TMP/1600-3200 mg SMZ total daily) for MRSA skin and soft tissue infections 1, 2

The American Academy of Pediatrics recommends 8-12 mg/kg/day TMP and 40-60 mg/kg/day SMZ, divided every 12 hours, for children over 2 months 3

The Centers for Disease Control and Prevention recommends 150 mg/m² TMP and 750 mg/m² SMZ daily, divided twice daily, given 3 consecutive days per week, for pediatric PCP prophylaxis 4

The American College of Obstetricians and Gynecologists recommends avoiding Septrin use in pregnancy at term 5
The American Academy of Pediatrics recommends obtaining baseline hemogram and monitoring monthly for hematological toxicity, particularly thrombocytopenia, in patients taking Septrin 3

The Centers for Disease Control and Prevention recommends an alternative schedule of 160/800 mg three times weekly on consecutive days for prophylaxis 6

The National Kidney Foundation advises avoiding concurrent use with methotrexate at treatment doses due to risk of severe bone marrow suppression, while lower prophylactic doses are generally tolerated 7
The National Kidney Foundation also recommends avoiding concurrent use with methotrexate at treatment doses due to risk of severe bone marrow suppression, while lower prophylactic doses are generally tolerated 8
The Centers for Disease Control and Prevention recommends not using trimethoprim-sulfamethoxazole in patients with G6PD deficiency due to hemolytic anemia risk 9

The American Academy of Family Physicians recommends trimethoprim-sulfamethoxazole (Bactrim) 160/800 mg three times weekly on consecutive days for Pneumocystis jiroveci pneumonia (PCP) prophylaxis in HIV-infected adults with CD4+ counts <200 cells/µL 10, 11

For patients with impaired renal function requiring three-times-weekly dosing, the American Academy of Family Physicians recommends a standard three-times-weekly regimen for those with CrCl >30 mL/min 10
For patients on hemodialysis requiring prophylaxis, the American Academy of Family Physicians recommends administering 500 mg three times weekly after dialysis 10

The refill instructions for trimethoprim-sulfamethoxazole (Bactrim) should be written as "Refills: As appropriate for clinical situation" according to the American Family Physician 10

The American College of Physicians and other medical societies recommend against using cotrimoxazole as first-line therapy for typical community-acquired pneumonia, instead preferring β-lactam antibiotics with or without macrolides, but it may be considered for documented MRSA pneumonia or specific susceptible pathogens when first-line agents have failed 12

For Burkholderia pseudomallei (Melioidosis), a weight-based dosing regimen is recommended, with 160/800 mg (1 double-strength tablet) every 12 hours for patients under 40 kg, 240/1200 mg (1.5 double-strength tablets) every 12 hours for patients between 40-60 kg, and 320/1600 mg (2 double-strength tablets) every 12 hours for patients over 60 kg, along with folic acid supplementation to prevent antifolate toxicity 12
For documented MRSA pneumonia, a dose of 5 mg/kg/dose IV every 8-12 hours is recommended as an alternative agent 13

The Infectious Diseases Society of America recommends considering cotrimoxazole for specific susceptible pathogens when first-line agents have failed, and also recommends adding folic acid supplementation when treating melioidosis or in patients at risk for folate deficiency 12