Does Septra (trimethoprim/sulfamethoxazole) come in a liquid formulation?

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Last updated: July 25, 2025View editorial policy

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Availability of Septra (Trimethoprim/Sulfamethoxazole) in Liquid Formulation

Yes, Septra (trimethoprim/sulfamethoxazole) is available in liquid formulation for patients who cannot swallow tablets, particularly for pediatric use.

Liquid Formulation Details

  • Trimethoprim/sulfamethoxazole (TMP-SMX) is available as an oral suspension with the following characteristics:
    • Standard concentration: 8 mg trimethoprim and 40 mg sulfamethoxazole per mL 1
    • Requires shaking well before measuring to ensure proper dosing 1
    • Can be administered with food to decrease gastrointestinal side effects 1
    • May be mixed with a small amount of juice or flavored syrup to improve palatability 1

Stability Information

Research has demonstrated that extemporaneously compounded oral suspensions of TMP-SMX (8 mg/mL trimethoprim and 40 mg/mL sulfamethoxazole) prepared from bulk powder remain stable for at least 90 days when stored in:

  • Amber plastic bottles at either refrigerated (5°C) or room temperature (25°C)
  • Amber plastic syringes at either refrigerated or room temperature 2

Dosing Considerations

  • For pediatric patients: The recommended dosing is 8-12 mg/kg/day based on the trimethoprim component
  • This is typically divided into 2 doses given every 12 hours 1

Clinical Applications

While the FDA has not approved TMP-SMX specifically for acne vulgaris treatment 3, it has been used off-label in dermatology for various skin conditions including acne 4.

The medication is officially approved for:

  • Urinary tract infections
  • Shigellosis
  • Acute otitis media in pediatric patients
  • Pneumocystis pneumonia 4

Important Precautions

  • TMP-SMX should not be used during pregnancy, especially in the third trimester, due to risks of neural tube defects, preterm birth, low birth weight, and kernicterus in newborns 1
  • Rare but serious adverse reactions include Stevens-Johnson syndrome and other severe skin reactions 3
  • Hematologic reactions such as anemia, thrombocytopenia, and agranulocytosis can occur, though rarely 5
  • The most common adverse effects are gastrointestinal intolerance and skin eruptions 5

Formulation Considerations

When compounding is necessary, it's important to note that suspensions prepared from commercial tablets may produce an unacceptable formulation with persistent foam that could result in inconsistent dosing. Suspensions prepared from bulk powder are preferred for stability and dosing accuracy 2.

References

Guideline

Antibiotic Therapy with Trimethoprim/Sulfamethoxazole

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Drug therapy reviews: trimethoprim-sulfamethoxazole.

American journal of hospital pharmacy, 1979

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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