C. diff Risk


Oral Bioavailability


Approximate Cost


250-500 mg po TID. Some guidelines may recommend higher dosing.

250-500 mg q24h
CrCl Less Than 10 mL/min

250-500 mg BID
CrCl 10-30 mL/min

250-500 mg TID
CrCl Greater Than 30 mL/min

General Information

Common Usage

Therapy of Streptococcal and Enterococcal infections as well as susceptible gram negative infections.

Commonly used for upper respiratory infections and urinary tract infections.

Adverse Effects

  •  Allergy/rash (immediate or delayed)

  •  Note EBV related rash

  •  Cytopenias

Major Interactions

Allopurinol - increased rash


Antimicrobial class: Aminopenicillin

Pregnancy category: B

Average serum half life: 1 hour

Biliary penetration: Therapeutic

CSF penetration: Moderate with inflamed meninges only

Lung penetration: Therapeutic

Urine penetration: Therapeutic