Given below is a mechanism of drug that increases force of contraction in heart failure.
Identify the most appropriate drug from the following.
(A) Spironolactone
(B) Salbutamol
(C) Propranolol
(D) Dobutamine
Salbutamol is a β2 receptor agonist that works by increasing cAMP within the smooth muscle. Its action cardiac muscle is not significant to be indicated as a drug in heart failure. Propranolol is a β blocker that doesn’t increase cAMP. Spironolactone is an aldosterone antagonist that is not related with this mechanism. Finally, dobutamine is a β 2 receptor agonist that specifically acts on cardiac muscle hence indicated for heart failure.
Given below is a ring system present in one of the drug indicated for heart failure. Identify it
(A) Verapamil
(B) Amiodarone
(C) Dobutamine
(D) Digoxin
Digoxin has significant interaction with all of the following except
(A) Amiodarone
(B) Verapamil
(C) Spironolactone
(D) Nifedipine
Amiodarone, verapamil and spironolactone all inhibit P-glycoprotein thereby decrease urinary excretion of digoxin leading to its toxicity. Nifedipine is a CCB that acts on vascular smooth muscle and has no interaction with digoxin.