Methicillin Resistant S Aureus
Mild
Textbook
May be effective against certain MRSA strains.
Trimethoprim-sulfamethoxazole may be an option for some MRSA strains that remain sensitive.
Source: Harrison 22e · p1054
Drug reference
trimethoprim-sulfamethoxazole
Antibacterial, Antiprotozoal
Antibacterial, Antiprotozoal
CDSCO approved
EXCRETION
—
not curated
INTERACTIONS
—
none in our sources
PREGNANCY
D
FDA category + note
Mechanism
Not yet extracted
Indications
CyclosporiasisIsosporiasisToxoplasmosis (alternative regimen, less effective)toxoplasmosiscommunity-acquired methicillin-resistant S. aureus (CA-MRSA) strainsAcute uncomplicated cystitis (women and men)Acute bacterial prostatitisPyelonephritisMethicillin-resistant infections (alternative to vancomycin/daptomycin)Oral therapy for skin and soft tissue infections resistant to methicillinSalvage therapy (combined with daptomycin)Brucellosis (acute nonfocal, for patients intolerant to tetracyclines, children, pregnant women)Combined with doxycycline for prophylaxis if rifampin is omitted for RB51 exposureNocardiosisProphylaxis against Pneumocystis disease (reducing nocardiosis risk)Treatment of *P. jirovecii* pneumonia (PCP)Prophylaxis of *P. jirovecii* pneumonia (PCP)
Dosing
- Adult
- 1 DS tablet bid
Side effects
Common
RashUrticariaNauseaVomitingHematologic abnormalitiesGastrointestinal effects (nausea, vomiting, diarrhea)FeverCytopeniasHepatitisHyperkalemia
Serious
- Hypersensitivity reactions (sulfonamide moiety)
- Leukopenia (with prolonged use)
- Thrombocytopenia (with prolonged use)
- Granulocytopenia (with prolonged use)
- Nephrotoxicity (more common at high doses)
- Hyperkalemia (more common at high doses)
- Hyponatremia (more common at high doses)
- Fetal risk in third trimester
- Anaphylactic reactions
- Anaphylactoid reactions
Pregnancy & lactation
Pregnancy
D
Drug interactions
Related guidelines
Other Unclassified drugs
Ask House about trimethoprim-sulfamethoxazole
Continue into a citation-backed clinical answer with the drug context already attached.
Sources: Goodman & Gilman 14e, Harrison 22e·Verified: 2026-05-10 · House clinical team