Monitor QTc in patients with increased risk

• GI upset
• Black Box: Tendinopathy and rupture. Potentially permanent and disabling damage to tendons, muscles, joints, and nervous system including peripheral neuropathies.
• C. difficile infection
• CNS toxicity including fatigue, confusion, memory impairment, delirium, psychosis
• Cardiac: QTc prolongation and risk for aortic aneurysm and dissection
• Severe blood glucose disturbances, including hypoglycemic coma
• Weakness exacerbation in myasthenia gravis

• CYP1A2 inhibitor – increases plasma concentrations of CYP1A2 substrates (examples: Zyprexa, Clozaril, melatonin, Requip, mirtazapine, tizanidine, triamterene, theophylline)
• Warfarin - Increased INR
• Divalent & trivalent cations including Al, Ca, Fe, Mg (antacids, dairy products, iron supplements, some enteral feeds) - Decreased absorption
• Cyclosporine - Increased levels of cyclosporine
• Methadone - Lowered seizure threshold
• Oral antidiabetic agents – increased risk of hyper and hypoglycemia, including hypoglycemic coma
• QTc prolongation - Increased risk with other agents that prolong QTc