Do not administer as IV bolus or IM. Patients w/ significant hepatic disease. Severe renal impairment (GFR <10 mL/min). Perform liver function tests/investigations immediately if signs/symptoms of liver dysfunction develops. Do not co-administer w/ ergot derivatives. Superinfection. C. difficile
-associated diarrhea. Consider discontinuation of therapy if CDAD occurs over 2 mth after. Institute appropriate fluid & electrolyte management, protein supplementation, antibiotic treatment of C. difficile
& surgical evaluation. Increased risk of prolonged cardiac repolarization; patients w/ congenital or documented QT prolongation, currently receiving treatment w/ other drugs known to prolong QT interval eg, anti-arrythmics (Class IA & III), cisapride & terfenadine, electrolyte disturbance, particularly hypokalemia & hypomagnesemia, bradycardia, cardiac arrhythmia, or severe cardiac insufficiency. Exacerbations of myasthenia gravis symptoms & new onset of myasthenia syndrome. Pregnancy & lactation. Childn.