Antimicrobials
Trimethoprim-Sulfamethoxazole

Trimethoprim-Sulfamethoxazole

C difficile risk
Low
Oral Bioavailability
Good (70 to 90%)
Cost
$0.08 (PO) $85.80 (IV)

Dosing

1 DS tabs PO BID

May require 15-20mg/kg/day of TMP IV in 4 divided doses for some indications: CNS infection, Pneumocystis jirovecii infection

15-20mg/kg/day of TMP IV in 4 divided doses

Note Quick method to calculate IV Septra dose in normal renal function

  • IV solution is supplied as 16 mg/mL TMP solution.

  • To obtain 16 mg/kg/day , order 1 mL IV solution per kg of body weight and divide total amount into 2-4 doses per 24hr period

Example 80 kg patient = 80 mL of Septra IV per 24hrs = 20 mL IV q6h

eGFR 0 - 10eGFR 10 - 30eGFR > 30Not recommended.

Consult pharmacy if use is deemed essential.50% of usual dosingUsual dosing

POIV1 single strength tablet q12h OR one double strength tablet twice daily2.5 to 5 mg/kg of TMP component every 24 hours

Dose after hemodialysis on dialysis days

Peritoneal Dialysis5 mg/kg of TMP component IV q8h

Depends on indication and type of renal replacement therapy

Pharmacist consult recommendedUse is generally not recommended

If necessary some regimens include:

  • PO: 1 single strength tablet q12h

  • IV: 5-10 mg/kg of TMP component q24h

General Information

  •  Urinary tract infections

  •  Susceptible MRSA infections

  •  Stenotrophomonas infections

  •  Pneumocystis jirovecii pneumonia (Treatment or prophylaxis)

Follow creatinine and electrolytes in patients at increased risk renal failure, hyperkalemia.

  •  Gastrointestinal upset common

  •  Bone marrow suppression

  •  Hyperkalemia

  •  Renal failure

  •  Hepatitis

  •  Aseptic meningitis

  •  Stevens Johnson syndrome/toxic epidermal necrolysis

  •  Other rashes

  • ACEi - Increased serum potassium level

  • Increases amantadine levels

  • Decreases cyclosporine

  • Methotrexate - Marrow suppression

  • Increases phenytoin

  • Increases rifampin

  • Increases INR with warfarin

IV Administration Dilute each 5mL amp in 100-125 mL NS or D5W. Administer dose over 60-90 min.

May dilute each 5 mL amp in 50-75 mL if fluid restricted but stability may be markedly decreased

Each 5 mL ampoule contains:

  • 80 mg Trimethoprim

  • 400 mg Sulfamethoxazole

Each single strength (SS) tablet contains:

  • 80 mg Trimethoprim

  • 400 mg Sulfamethoxazole

Each double strength (DS) tablet contains:

  • 160mg Trimethoprim

  • 800 mg Sulfamethoxazole

EH prescribing restrictions None

Community IV Formulary (Metro Area) NO

Tablets may be crushed for NG administration; Liquid formulation is also available.

10mL Oral liquid = 1 single strength (SS) tablet

20mL Oral liquid = 1 double strength (DS) tablet

OPEN BENEFIT (PO) No prescribing restrictions

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