Trimethoprim-Sulfamethoxazole

C. diff Risk

Low

Oral Bioavailability

Excellent

Approximate Cost

IV:$$$
PO:$

Dosing

PO: 1-2 DS tabs PO BID

IV: 10-20mg/kg/day of TMP IV in 3-4 divided doses

  • Use adjusted body weight for dosing

  • May consider TBW for serious infections

  • TMP/SMX has high oral bioavailability – consider initiating with/switching to oral therapy when patient tolerating orals

  • When switching to oral therapy, consider that a single-strength tablet has 80mg of TMP, a double-strength tablet 160mg of TMP.

CrCl >50 mL/minCrCl 10 - 50 mL/minCrCl <10 mL/min (ESRD not on HD)Dialysis (HD)Dialysis (CRRT)10 mg TMP/kg/day IV divided Q6 - 12h5 - 7.5 mg TMP/kg/day IV divided Q12 - 24h2.5 - 5.0 mg TMP/kg IV Q24h2.5-5mg TMP/kg/day Q24h5-7.5mg TMP/kg/day divided Q12-24h

CrCl >50 mL/minCrCl 10 - 50 mL/minCrCl <10 mL/min (ESRD not on HD)Dialysis (HD)Dialysis (CRRT)15 - 20 mg TMP/kg/day IV divided Q6 - 12h10 - 15 mg TMP/kg/day IV divided Q12 - 24h5 - 10 mg TMP/kg IV Q24h2.5-5mg TMP/kg/day Q24h5-7.5mg TMP/kg/day divided Q12-24h

Creatinine Clearance >50mL/min/1.73m²Creatinine Clearance 15-30mL/min/1.73m²Creatinine Clearance ≤10mL/min/1.73m²5mg TMP/kg/dose Q12H2.5mg TMP/kg/dose Q12H5mg TMP/kg/dose Q24H

Creatinine Clearance >50mL/min/1.73m²Creatinine Clearance 15-30mL/min/1.73m²Creatinine Clearance ≤10mL/min/1.73m²5mg TMP/kg/dose Q6-8H5mg TMP/kg/dose Q8-12H5mg TMP/kg/dose Q12-24H

General Information

  • Nausea

  • Vomiting

  • Hypersensitivity reactions, bone marrow suppression

  • Hyperkalemia

Laboratory

  • With high dose: consider baseline and periodic measurement of Cr (dose adjustment and nephrotoxicity assessment)

  • CBC

  • K

  • LFTs

Clinical

  • Hypersensitivity

  • GI effects

  •  ACEi - increased serum potassium level

  •  Increases amantadine levels

  •  Decreases cyclosporine

  •  Methotrexate - marrow suppression

  •  Increases phenytoin

  •  Increases rifampin

  •  Increases INR with warfarin

Antimicrobial class: Sulfonamide - Antifolate

Pregnancy category: C

Average serum half life: 10 hours

Biliary penetration: Moderate

CSF penetration: Therapeutic

Lung penetration: Therapeutic

Urine penetration: Therapeutic

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