Sotalol is a voltage gated potassium channel blocker that present on the heart and indicated as antiarrhythmic agent. Minoxidil, chromokalim and nicorandil are Ach-sensitive potassium channel blockers which are present on vascular smooth muscle.
(D) All of the above
Calcium channel blockers chemically belong to three classes. Verapamil is a phenylalkylamine, diltiazem is a benzothiazepine and nifedipine, nimodipine are dihydropyridines. Among these verapamil is selective for cardiac muscle whereas dihydropyridines are selective for smooth muscle. Diltiazem acts on both cardiac as well as smooth muscle.
Dihydropyridines like nifedipine are selective for smooth muscle and produce direct vasodilatation. Because of this vasodilatation, perfusion pressure decreases and baroreceptor reflex is stimulated leading to increased central sympathetic discharge. This results in release of noradrenaline and adrenaline which act on heart to produce tachycardia. Verapamil directly acts on cardiac muscle hence produces bradycardia.
(C) Decreased thyroid function
Sodium nitroprusside is given by IV route and it can be converted into thiocyanate in the body which on accumulation may inhibit thyroid function.
(A) Accumulation of bradykinin
(B) Accumulation of thiocyanate
(C) Depletion of thiol groups
Sodium nitroprusside is given by IV route and it can be converted into thiocyanate in the body which on accumulation may produce toxic effects like inhibition of thyroid function, weakness and nausea.