C. diff Risk


Oral Bioavailability


Approximate Cost

IV-$4/d PO-$3/d


PO: 500-750mg po q12h

IV: 400mg IV q8-12h

General Information

Common Usage

Pseudomonal and other gram negative infections of urinary tract, bone/joint, abdomen, and other sites.

Drug Monitoring

Monitor QTc in patients with increased risk

Adverse Effects

  • QTc prolongation

  • Dysglycemia

  • Tendinopathy and rupture

  • GI upset

  • Rash

  • Retinal detachment

  • CNS toxicity including confusion, psychosis

  • Weakness exacerbation in myasthenia gravis

Major Interactions

CYP1A2 inhibitor - multiple interactions possible

QTc prolongation - Increased risk with other agents that prolong QTc

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

Cyclosporine - increased levels of cyclosporine

Warfarin - increased INR

Methadone - lowered seizure threshold


Antimicrobial class: Fluoroquinolone

Pregnancy category: C

Average serum half life: 4.0

Urine penetration: Therapeutic

Lung penetration: Therapeutic

CSF penetration: Moderate

Biliary penetration: Therapeutic