Miscellaneous Cardiac Drugs Flashcards
Give the common clinical indication for the use of Nicorandil.
Used for prevention and treatment of chest pain in patients with stable angina.
Nicorandil (or a long acting Nitrate) can be used in first line drugs (beta blockers/ CCBs) used individually or in combination are insufficient or not tolerated.
1) What class of drug is Nicorandil?
2) What is the basic mechanism of action of Nicorandil?
3) What are the overall effects of Nicorandil?
1) Nitrate and potassium channel opener.
2) Activates K+ channels > efflux of K+ leads to cell membrane hyperpolarisation > subsequent inactivation of Ca2+ channels > decrease in free intracellular Ca > smooth muscle relaxation and vasodilation (as calcium required for contraction) > reduced cardiac preload > reduced systemic and coronary resistance.
3) Nitrate actions cause arterial and venous vasodilation.
Potassium channel opener effects: improves myocardial perfusion, decreases myocardial work, decreases oxygen demand.
Give 3 adverse effects of using Nicorandil.
Flushing, dizziness and headache (due to vasodilation).
Nausea, vomiting and hypotension.
GI, skin or mucosal ulceration which only responds to withdrawal of treatment.
Name 3 conditions which would mean that you shouldn’t prescribe Nicorandil.
Poor left ventricular function, hypotension, pulmonary oedema.
Prescription of Nicorandil to patients with these conditions can worsen them.
Which class of drugs should Nicorandil not be prescribed in conjunction with and why?
Should not be combined with phosphodiesterase inhibitors (e.g. Sildenafil) as phosphodiesterase inhibitors significantly enhance the hypotensive side effects of Nicorandil.
Describe how Nicorandil would be prescribed.
Only available PO. Started at a low dose of 5-10mg BD and increased to 20-30mg BD as patient becomes tolerant of vasodilator adverse effects.
What needs to happen if a patient’s symptoms are not controlled using two anti-anginal drugs?
Refer to a cardiologist for review and consideration of angiograophy and revascularisation.
Name 2 anti-angina drugs which are not Nitrates.
State their class and basic MoA.
1) Ivabridine - specific sinus node inhibitor - reduces heart rate by selectively inhibiting funny channels in the heart, prolonging diastolic depolarisation and lowering heart rate. Overall lowers SAN pacemaker firing rate, reducing heart rate and myocardial oxygen demand.
2) Ranolazine - late Sodium current inhibitor - Inhibits Sodium and potassium ion channel currents. Inhibition of potassium rectifier channels prolongs ventricular action potential and inhibition of late Sodium currents increases myocardial function.
