This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Adverse Drug Effect, Subject name: Pharmacology
Drugs that do not increase QT interval: (PGI Nov 2010) 
Select and explain. 
A. Amiodarone, B. Quinidine, C. Digitalis, D. Amitryptyline
C: Digitalis
Answer: C: Digitalis 
Explanation: Ans: C (Digitalis) "Digitalis cause shortening of QT interval"- KDT 6th/495Drugs that Prolong Q-T intervalAntiarrhythmicsQuinidineQ, procainamideQ, disopyramide. propafenone, AmiodaroneQ, SotalolAntimicrobialQuinine, mefloquine, artemisinin, halofan- trine, sparfloxacin, gatifloxacinAntihistaminicTerfenadineQ, astemizole, ebastineAntidepressantsAmitryptyline & other tricyclicsAntipsych oticsThioidazine, risperidoneProkineticsCisaprideQ