Please check your internet connection and try again.
## Septran (Trimethoprim/Sulfamethoxazole)
### Overview
Septran is a combination antibiotic containing trimethoprim and sulfamethoxazole, which work synergistically to inhibit bacterial folic acid synthesis.
### Primary Indications
* Urinary tract infections (UTIs)
* Pneumocystis jirovecii pneumonia (PJP) prophylaxis and treatment
* Shigellosis
* Certain respiratory tract infections
* Traveler's diarrhea
### Adult Dosing
* **UTIs and Shigellosis:** 160 mg trimethoprim/800 mg sulfamethoxazole (one double-strength tablet) every 12 hours for 3-7 days (UTI) or 5 days (shigellosis).
* **PJP Prophylaxis (HIV-infected patients):** 160 mg trimethoprim/800 mg sulfamethoxazole once daily.
* **PJP Treatment:** 15-20 mg/kg/day trimethoprim and 75-100 mg/kg/day sulfamethoxazole, divided into 4 doses, for 14-21 days. (This can also be expressed as 3 double-strength tablets every 6 hours for 14-21 days for adults weighing around 60kg, but calculation per kg is preferred).
* **Traveler's Diarrhea:** 160 mg trimethoprim/800 mg sulfamethoxazole every 12 hours for 3-5 days.
* **Maximum Daily Dose:** Generally not to exceed 4 double-strength tablets (320 mg trimethoprim/1600 mg sulfamethoxazole) per day, except for severe PJP treatment.
### Pediatric Dosing
* Dosing varies significantly by indication and weight. Consult specific guidelines or package insert for precise dosing for UTIs, PJP prophylaxis, and treatment.
* **General guideline for UTIs (age > 2 months):** 8 mg/kg/day trimethoprim and 40 mg/kg/day sulfamethoxazole, divided into two doses.
### Dose Adjustments
* **Renal Impairment:** Dose adjustment is necessary based on creatinine clearance (CrCl).
* CrCl > 30 mL/min: Standard dose.
* CrCl 15-30 mL/min: Half the standard dose.
* CrCl < 15 mL/min: Avoid use.
### Contraindications
* Hypersensitivity to trimethoprim or sulfonamides.
* History of drug-induced immune thrombocytopenia with either agent.
* Megaloblastic anemia due to folate deficiency.
* Infants < 2 months of age (risk of kernicterus).
* Severe renal or hepatic insufficiency where drug concentration cannot be monitored.
* Documented G6PD deficiency (risk of hemolytic anemia).
### Adverse Effects
* **Common:** Nausea, vomiting, rash, hyperkalemia.
* **Serious:** Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), severe rash (e.g., DRESS), photosensitivity, hepatic necrosis, bone marrow suppression (anemia, leukopenia, thrombocytopenia), hyperkalemia, hypoglycemia, renal damage.
### Key Drug Interactions
* **Warfarin:** Increased INR. Monitor INR closely.
* **Methotrexate:** Increased methotrexate levels and toxicity.
* **ACE inhibitors/ARBs/Potassium-sparing diuretics:** Increased risk of hyperkalemia.
* **Potassium supplements:** Increased risk of hyperkalemia.
* **Certain oral hypoglycemics (e.g., sulfonylureas):** Increased risk of hypoglycemia.
* **Cyclosporine:** Increased cyclosporine levels.
### Monitoring
* Complete blood count (CBC) with differential and platelet count, especially with prolonged therapy or in immunocompromised patients.
* Renal function (BUN, creatinine).
* Electrolytes, particularly potassium.
* Liver function tests (LFTs) if clinically indicated.
* For patients on warfarin, monitor INR.
### Clinical Pearls
* Advise patients to drink plenty of fluids to prevent crystalluria.
* Instruct patients to report any rash, fever, sore throat, or mouth sores immediately.
* Photosensitivity can occur; advise sun protection.
* TMP/SMX can interfere with some urine drug screening tests.
* Dosing for specific indications and patient populations should be confirmed with current prescribing information or local protocols.
***
*Please verify current prescribing information for complete details and to ensure accuracy.*
