Nicorandil

Question 1

Mechanism of action?

Answer 1

As a nitrate, it is an arterial &venous vasodilator. It activates the K ATPase channels, K efflux causes hyperpolarisation of the cell &subsequent inactivation of voltage-gated Ca channels. Net effect : decreased intracellular Ca which induces relaxation &vasodilatation. This reduces the cardiac preload, decreases systemic &vascular resistance, improves myocardial perfusion &lowers myocardial work &oxygen demand. Ultimately, it reduces the frequency &severity of angina attacks.

Question 2

Indications?

Answer 2

stable angina : first choice treatment are b-blocker &/or Ca channel blockers. Nicorandil is used if these drugs are insufficient or nontolerated.

Question 3

How is it taken?

Answer 3

Exclusive oral preparations. Doses increase is progressive (from 5mg up to 30mg).

Question 4

Important AE?

Answer 4

Related to vasodilation properties : dizziness, flushing, headaches, N&V &hypotension. Less frequently, gastrointestinal &skin ulcerations, necessitating withdrawal.

Question 5

Important cautions?

Answer 5

Patients with hypotension, pulmonary oedema &poor left ventricular function. Nicorandil can worsen these situations.

Question 6

Important interactions?

Answer 6

With phosphodiesterase inhibitors, increased chances of severe hypotension.

Question 7

Venous dilatation?

Answer 7

reduces preload

Question 8

Arterial dilatation?

Answer 8

reduces afterlaod.