Antianginal Drugs


Antianginal Drugs


Angina medications
are used for angina pectoris or chest pain. 

The types of chest
are chronic stable angina (which is associated with atherosclerosis), unstable
angina (early stage of progressive coronary artery disease), and vasospastic angina
results from spasms in the layer of smooth muscle that surrounds
atherosclerotic coronary

The three main classes of drugs used to treat
angina pectoris are nitrates and nitrites, betablockers, and calcium channel blockers.

The goal of the treatment is:


Minimize the frequency of attacks and decrease the duration and intensity of
angina pain

2. Improve the patients functional capacity with as few adverse effects as possible


Increase blood flow to ischemic heart muscle and decrease myocardial oxygen

4. Prevent or delay the
worst possible outcome, which is a myocardial infarction


Nitrates and Nitrites


Nitrates are available on many forms including sublingual, chewable tablets, oral capsules/tablets,
 IV  solutions,  transdermal patches,  ointments

They are broken down into rapidacting forms and longacting forms. 

The rapidacting forms include sublingual and IV solutions. 

These are used to treat
acute angina attacks. 

The longacting forms are used to prevent angina episodes

Mechanism of Action

Nitrates dilate all blood vessels; however, they predominately affect venous
vascular beds and have a dosedependent arterial vasodilator effect. This
vasodilation happens because of relaxation of smooth muscle cells.

1. Vasodilation
results in reduced myocardial oxygen demand and therefore more
oxygen to ischemic myocardial tissue and reduction of angina symptoms.

2. By causing venous dilation, the nitrates reduce venous return
and in turn reduce
enddiastolic volume (preload) and results in a lower left
ventricular pressure.

Adverse Effects

Headache is the most common undesirable effect. If nitrateinduced vasodilation


occurs too rapidly, reflex tachycardia occurs which is characterized by an increase in heart rate. This is because the cardiovascular system tries to overcompensate. Other adverse effects include postural hypotension and tolerance may develop.



The  betablockers
 classified  as
 antianginal  are  atenolol,  metoprolol

(Lopressor), propranolol (Inderal) and nadolol (Corgard).


Mechanism of Action


Beta blockers block beta1receptors on the heart. This allows:


1.  Decrease  in  heart
 which  decreases  myocardial  oxygen
 and increases oxygen delivery to the heart.

2.  Decreases  myocardial contractility helping
 conserve  energy  or  decrease demand.

3. After an MI, a high level of catecholamines irritates the  heart causing an
imbalance in supply and demand, which can lead to lifethreatening dysrhythmias. Betablockers block the  harmful effects of catecholamines improving survival
after an MI.

4. The heart spends more time in diastole than in systole.




1. Most effective in the
treatment of exertional angina


2. Antihypertensive treatment

3. Cardiac dysrhythmias


4. Cardioprotective effects following an MI


5. Approved for migraine headaches, essential tremors and tachycardia caused by
stage fright.

Adverse Effects


Adverse effects include decreased in heart rate, cardiac output and cardiac contractility. 

Therefore, bradycardia, hypotension and AV block. In the CNS, it can cause dizziness, fatigue, depression, and lethargy. 

In diabetic patients, beta
blockers can cause hyperglycemia and/or hypoglycemia as well
masks the signs
and symptoms of hypoglycemia
and the patients might not be able to tell when
exactly the sugar is too low.

Calcium Channel Blockers


CCBs that are used for the treatment of chronic stable angina include amlodipine (Norvasc), diltiazem (Cardizem),  nicardipine (Cardene), nifedipine (Procardia), and verapamil.

Mechanism of Action


calcium from entering the muscle of the heart to prevent muscle contraction and promote muscle relaxation. 

the muscle relaxes, it causes the blood
vessels to dilate and therefore increases the blood flow to the ischemic heart, which in turn increases the oxygen supply and helps shift the supply/demand ratio
to normal. 

CCBs cause peripheral arterial vasodilation decreasing systemic vascular  resistance and  decreasing the
 workload  of  the
 which  leads  to
decrease in myocardial oxygen demand.



Firstline treatment for:


1. Angina


2. Hypertension

3. Supraventricular tachycardia


Also, used to treat coronary artery spasms (prinzmetal angina) as well as the short
– term  management of  atrial
 fibrillation,  atrial  flutter,  migraine
 headaches,  and Raynauds disease.

Adverse Effects


Limited adverse effects and those are related to overexpression of therapeutic effects including hypotension, palpitations, tachycardia or bradycardia,
constipation, nausea, dyspnea.

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