Contraindicated in patients w/ history of hypersensitivity. Discontinue treatment at the 1st signs of rash, pain, myalgia or tenodynia. May be harmful to the liver & kidney. Patients w/ known or suspected CNS disorders that predispose to seizure (eg, severe cerebral arteriosclerosis, epilepsy); w/ causative risks of QT prolongation (eg, elderly, CV disease especially arrhythmia, HTN, hypokalemia). Avoid concomitant use w/ drugs known to cause QT prolongation [eg, antiarrhythmics class IA (eg, quinidine, procainamide), class III (eg, amiodarone, sotalol), cisapride, erythromycin, antipsychotics & TCAs]; patients w/ ongoing proarrhythmic conditions eg, significant bradycardia or acute myocardial ischemia. May cause phototoxic reactions or severe hypersensitivity eg, toxic epidermal necrolysis, Stevens-Johnson syndrome, erythema multiforme. May alter blood glucose; DM patients. Monitor blood glucose carefully. Peripheral neuropathy. C.difficile
-associated diarrhea. Concomitant use w/ warfarin. Increased risk of tendonitis & tendon rupture in elderly patients aged >60 yr, those taking corticosteroids & those w/ kidney, heart or lung transplants. Avoid in patients w/ known history of myasthenia gravis. Prolonged therapy may lead to superinfection. Mild, moderate or severe hepatic insufficiency (Child-Pugh class A, B or C). Pregnancy & lactation. Childn <18 yr. Elderly especially those on corticosteroids.