Cisapride, ventricular arrhythmias caused

Telithromycin may cause clinically significant QTc prolongation and increased risk of ventricular arrhythmia in predisposed patients. It should not be used in patients with prolonged QT syndrome, uncorrected hypokalemia or hypomagnesemia, profound bradycardia, or in patients receiving certain antiarrhythmics (e.g., quinidine, procainamide, amiodarone) or other agents that prolong QTc (e.g., cisapride, pimozide). 

Absolute aprepitant is contraindicated in patients who are hypersensitive to any component of the product. Aprepitant is a weak-to-moderate (dose-dependent) cytochrome P450 isoenzyme 3A4 (CYP3A4) inhibitor. Aprepitant should not be used concurrently with pimozide, terfenadine, astemizole, or cisapride. Dose-dependent inhibition of CYP3A4 by aprepitant could result in elevated plasma concentrations of these drugs, potentially causing serious or life-threatening ventricular arrhythmias. 

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