Antimicrobials
Trimethoprim/Sulfamethoxazole

Trimethoprim/Sulfamethoxazole

Low
Excellent
IV: $$$ PO: $ (Tablet)

Spectrum of Activity

General Information

Pneumonia in an Immunocompromised Host:

  • TMP-SMX may not be appropriate if significant neutropenia or post-BMT and not yet engrafted

Cutaneous Abscesses, Furuncles, Carbuncles, and Boils (with or without cellulitis):

  • If there are risk factors for MRSA or failed 1st-line outpatient treatment despite adequate adherence:

    • PO: TMP-SMX or Clindamycin or Doxycycline (if ≥ 8 yrs old)
  • Use Clindamycin or Doxycycline if Group A strep is strongly suspected despite failure of 1st-line treatment

  • TMP-SMX does not cover Streptococcal infections well

ODB covered (tablet)

Stevens Johnson syndrome/toxic epidermal necrolysis, other rashes, gastrointestinal upset is common, bone marrow suppression, hyperkalemia, renal failure, hepatitis, aseptic meningitis

  • CBC, renal function test, liver function test, urinalysis; observe for change in bowel frequency

  • Sulfa antibiotics have been shown to displace bilirubin from protein binding sites which may potentially lead to hyperbilirubinemia and kernicterus in neonates and young infants; do not use in neonates; avoid use in infants <2 months unless other options are not available (eg, Pneumocystis)

May be taken with or without food

  • Maintain fluid intake. May be given with food

  • Do not give to infants <1 month old due to risk of kernicterus

  • Special Access Program authorization required for suspension, which is no longer marketed in Canada

  • Brand names: Cotrimoxazole, Septra, Bactrim

  • Trimethoprim and Sulfamethoxazole (TMP/SMX) is available in combination as a fixed dose ratio of 1:5