Friday, 11 December 2015

PGIMER entrance Preparations | Use of beta blockers and calcium channel blockers


Combination use of beta blockers and calcium channel blockers cause 

A. Heart block 
B. Hypertension 
C. Hypotension 
D. Bradycardia 
E. Tachyarrhythimias



Ans. A. Heart block ; (D) Bradycardia : 
• When β-blockers given with verapamil or diltiazem, they produce:-
— Additive sinus depression, conduction defects or asystole may occur resulting in marked bradycardia, A-V block. 
— Cardiac arrest may occur. 
• Nifedipine causes tachycardia, increased contractility and cardiac output due to reflex sympathetic stimulation, propranolol has been safely used with Nifedipine 
• Propranolol, initially causes little change in BP (due to blockade of β-mediated vasodilation but on continued use fall in BP due to chronically reduced CO.). 
— Verapamil dilates arterioles and some α-blocking activity — BP is only moderately lowered.