Angina drugs Flashcards
First line treatment of angina
nitrates
CCBs
beta blockers
nitrates- examples
nitroglycerin
nitrate MOA
- dilation of veins
- dilation of large arteries
- dilation of coronary collateral
- prevent vasospasm (variant angina)
nitrate can be converted into nitric oxide
nitrate- pharmacokinetics
- low oral bioavailability due to fast metabolism by the liver, use sublingual route instead
- rapid onset, short duration of action, excreted by kidneys
nitrate- complications
tachyphylaxis- 8-12 hours of nitrate free period, usually at night
dependence- arterial and digital vasospasm if withdraw suddenly, have to be careful when without with chronic patients
nitrate- drug cautions
- do not take with PDE5 inhibitors (slidenafil) because it causes hypotension then reflex tachycardia
- and soluble guanylate cyclase stimulators such as riociguat
nitrate- contraindications and side effects
- orthostatic hypotension, tachycardia, headache
contraindicated in increased intracranial pressure patients
nitrate- route of administration
- sublingual: immediate relieve
- oral: need high dose or sustained release formulation for prophylaxis
- subcutaneous: prophylaxis for nocturnal angina
- buccal or transmucosal: above the incisor under the upper lip, prophylaxis for a short time
- IV: coronary spasm
CCBs
- artery and arterioles vasodilation
- reduce force of contraction of the heart
- reduce coronary spasm (variant angina)
- vascular selective one may cause hypotension (reduce coronary blood flow) and tachycardia (worsen)
beta blockers
- reduce force and rate of contraction of the heart
- increasing the diastole duration, coronary blood flow duration and perfusion to the myocardium
- causes vasospasm (contraindicated in variant angina)
nicorandil- MOA
- similar to nitrate: stimulate the guanylate cyclase activity
- activate the ATP-sensitive K channels in VSCM: hyperpolarization of smooth muscle and vasodilation
- reduce coronary spasm (variant angina)
- act on both artery and venous
nicorandil- side effects
hypotension, tachycardia, headache
trimetazidine- MOA
- inhibit the 3-KAT
- inhibit the fatty acid oxidation, have to switch to glucose oxidation for more efficient utilization of cardiac oxygen
- usable in low heart rate and bp patients
trimetazidine- side effects
parkinson syndrome
ranolazine- MOA
- inhibit the late Na current (usually seen in ischemia)
- reduce the Na influx and therefore reduce the influx of Ca by Na Ca exchanger
- reduce intracellular Ca overload and contractility
- reduce the cardiac workload
ranolazine- contraindications and side effects
- do not use with CYP3A4 inhibitors
- inhibit the potassium current -> don’t use in long QT syndrome patients and prolong the duration of action potential
Ivabradine- MOA
- inhibit the HCN channels of SA node to reduce the funny current, reducing the heart rate
- reduce the cardiac workload
- increase coronary perfusion
ivabradine- side effects
- bradycardia
- atrial fibrillation (take over by the AV node)
ivabradine- use
alternative for patients not responding to beta blockers
ivabradine- cautions and contraindications
- do not use with CYP3A4 inhibitors
- do not use with CCBs, hypokalemia inducing drug e.g. loop and thiazide, long QT inducing drugs e.g. sotalol and quinidine
- must have 70 bpm, chronic stable angina with normal sinus rhythm
- do not use in hypotension patients
- do not use in pregnant or possibly will be pregnant patients
Combination therapy
vascular + cardiac
CCBs + nitrate
dihydropyridine + beta blockers
beta blockers + nitrate
