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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Which of the following drugs, if given with terfena dine, can cause ventricular arrhythmias
assistant
The correct answer is  Fexofenadine:- It is the active metabolite of Terfenadine, the first nonsedating SGA that was withdrawn because of several deaths due to polymorphic ventricular tachycarida (Torsades de pointes) occurring with its higher doses or when it was coadministered with CYP3A4 inhibitors (erythromycin, clarithromycin, ketoconazole, itraconazole, etc.). mech of toxicity:- Toxicity is based on blockade of delayed rectifier K+ channels in the hea at higher concentrations. Astemizole is another SGA banned for the same reason. Ref:- kd tripathi;pg num:-166