Please note: This is for information only.

Refer to local guidelines for treatment recommendations


Co-trimoxazole = sulphamethoxazole + trimethoprim.

  • Usual adult treatment dose: 120mg/kg/day in 4 divided doses
  • Usual adult prophylaxis dose: up to 960mg bd, 3 times per week.
  • Can be given IV or orally
  • Renally excreted therefore reduce dose if renal impairment.
  • Reserved for the treatment and prevention of PCP and toxoplasmosis due to serious adverse effects (Stevens-Johnson syndrome, blood dyscrasias).
  • Penetrates well into CSF and tissue.


  • PCP – treatment and prophylaxis
  • Toxoplasmosis – treatment and prophylaxis

Active against most strains of:

  • Pneumocystis carinii
  • Nocardia
  • Staphylococcus aureus – including MRSA
  • Escherichia coli
  • Klebsiella spp
  • Other Coliforms
  • Moraxella
  • Haemophilus
  • Stenotrophomonas maltophilia
  • Listeria

Not active against most strains of:

  • Anaerobes
  • Strep pneumoniae