Co-trimoxazole (TMP/SMX)

Low

Excellent

IV$100/d PO$1/d

Spectrum of Activity

General Spectrum of Activity

Antibiogram Data

Dosing

General Pediatric

Women's Health

800 mg/160 mg (1 DS) tablet PO q12h

Neonatal

Use caution in infants <2 months old due to risk of kernicterus.

Renal

Renally cleared, requires dosage adjustment with changes in renal function. Consult a pharmacist for renal dosing.

General Information

Common Usage

Urinary tract infections
Susceptible MRSA infections
Stenotrophomonas infections
Pneumocystis jirovecii pneumonia (treatment or prophylaxis)

Drug Monitoring

Creatinine and electrolytes in patients at increased risk renal failure
Potassium
CBC

Adverse Effects

Stevens Johnson syndrome/toxic epidermal necrolysis & other rashes
Gastrointestinal upset (common)
Bone marrow suppression
Hyperkalemia
Renal failure
Hepatitis
Aseptic meningitis

Major Interactions

Methotrexate- marrow suppression
Increases phenytoin
Increases INR with warfarin

Additional Information

Dosing is based on the trimethoprim (TMP) component

Pediatric strength tablets:100mg SMX/ 20 mg TMP
Regular strength tablets: 400mg SMX/ 80 mg TMP
Double strength tablets: 800 mg SMX/ 160 mg TMP
Suspension: (per 1 mL): 40 mg SMX/8 mg TMP
Injection: (per 1 mL): 80 mg SMX/16 mg TMP

Pharmacology

Antimicrobial class: Sulfonamide - Antifolate

Route of Elimination: Both excreted in urine as metabolites and unchanged drug

Average serum half life: TMP (prolonged in renal failure)

Newborns: ~19 hours; range: 11-27 hours
Infants 2 months to 1 year: ~4.6 hours; range: 3-6 hours
Children 1-10 years: 3.7-5.5 hours
Children and Adolescents >10 years: 8.19 hours
Adults: 6-11 hours

SMX: 9-12 hours, prolonged in renal failure (Adult data)