C. diff Risk


Oral Bioavailability


Approximate Cost


500-750mg PO/IV daily

General Information

Common Usage

Lower respiratory infection (CAP, HAP), intraabdominal infection, UTI

Drug Monitoring

Monitor QTc in patients with increased risk

Adverse Effects

QTc prolongation


CNS toxicity including confusion, psychosis

Tendinopathy and rupture

GI upset

Weakness exacerbation in myasthenia gravis


Major Interactions

Other QTc prolonging agents

Di- & Trivalent cations including Al, Ca, Fe, Mg (antacids, dairy products, iron supplements, some enteral feeds) - decreased absorption

NSAIDs - increase seizure risk

Warfarin - increased INR

Additional Information

FDA Black Box warning against use in uncomplicated UTI, acute bacterial sinusitis, and acute exacerbation of chronic bronchitis where alternatives exist due to serious adverse side effects
May exacerbate muscle weakness in persons with myasthenia gravis. Avoid Use.


Antimicrobial class: Fluoroquinolone

Pregnancy category: C

Average serum half life: 7.0

Biliary penetration: Therapeutic

Lung penetration: Therapeutic

Urine penetration: Therapeutic