C. diff Risk


Oral Bioavailability


Approximate Cost

Spectrum Of Activity


500-750 mg PO BID

400 mg IV q8-12h

General Information

Drug Monitoring

Monitor QTc in patients with increased risk

Adverse Effects

  • QTc prolongation

  •  Dysglycemia

  •  CNS toxicity including confusion, psychosis

  • Tendinopathy and rupture

  • GI upset

  • Weakness exacerbation in myasthenia gravis

  • Rash

  • Retinal detachment

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

  •  Decreases phenytoin levels

Additional Information

May exacerbate muscle weakness in persons with myasthenia gravis. Avoid Use.


Antimicrobial class: Fluoroquinolone

Pregnancy category: C