Drugs used for controlling heart rate intraoperatively | AIIMS Based MCQ

MI of following drugs are used for controlling heart rate intraoperatively EXCEPT 

A. Propranolol/metoprolol 
B. Verapamil 
C. Esmolol 
D. Procainamide

Ans. D. (Procainamide) 

Procainamide is a class of antiarrhythmic agent (la) which blocks fast sodium channels but prolongs action potential duration. It is rarely used during anesthesia because of their propensity to produce hypotension. It is effective in the treatment of ventricular tachydysrhythmia. Verapamil effectively controls heart rate. Dose is 5—10mg IV over 1—3 mm. Propranolol/metoprolol and esmolol are B-adrenergic-blocking drugs that are effective for controlling the heart rate intraoperatively. 

Doses: 
Metoprolol : 5—15 mg IV over 20 min.
Esmolol : 0.5—1 mg/kg every 60 min.