When does angina pain occur?

Lack of O2 supply to myocardium to cardiac demand.

What determines cardiac O2 demands?

What helps relieve it?

1.  HR

2.  Contractility

3.  Preload and Afterload

Drugs that reduce these factors help relieve angina

What are the 3 forms of angina pectoris?

1.  Chronic stable angina

2.  Variant (vasospastic) angina

3.  Unstable angina

What is the cause of stable angina?

Underlying coronary artery atherosclerosis

What is the underlying cause of variant angina?

coronary artery spasm

How do drugs relieve stable anginal pain?

By decreasing the cardiac oxygen demand. 

DOES NOT increase oxygen supply

How do drugs relieve variant angina?

By increasing cardiac oxygen supply, 

DO NOT decrease oxygen demand.

What are the oldest and most frequently used antianginal drugs?

Organic nitrates

Nitroglycerin is drug of choice for acute anginal attack.

How does NTG relieve pain of stable angina?

Dilating veins, which decreases venous return, which decreases preload, which decreases oxygen demand.

How does NTG relieve variant anginal pain?

By relaxing coronary vasospasm,

which increases oxygen supply.

How is NTG administered?

SL vs PO to avoid first-pass effect since it is rapoidly inactivated by the liver.  Lipid soluble so easily and quickly absorbed SL.

What are the 3 characteristic side effects of NTG?

1.  Headache

2.  Hypotension

3. Reflex Tachycardia

All 3 occur secondary to vasodilitation.

How can you prevent reflex tachycardia with NTG?

Beta blocker; verapamil or diltizaem

For NTG to cause vasodilitation, what must happen first?

Must be converted to nitric oxide, its active form.  This requires a sulfhydryl source.

Continuous use of NTG can cause tolerance within 24 hrs.

Why?

Mechanism may be depletion of sulfhydril groups.

How can you best prevent tolerance of NTG?

1. Use  lowest effective dosage

2. Long-acting formulation should be used intermittently with at least 8 hours of drug free time evey day -

usually at night.

When is SL NTG typically used?

To abort an acute angina attack and to provide acute prophylaxis when exertion is expected.

Taken prn

When are long duration NTG formulas used?

(patches, sustained release oral capsules)

Extended protection against anginal attacks

Administration on fixed schedule but with a minimum of 8 hour break.

What one drug should NTG  not be used with?

Viagra

How do beta blockers prevent stable angina?

Primarily by decreasing HR and contractility, which reduces cardiac oxygen demand.

Beta Blockers are used for variant angina?

True or False

False

How do CCB's relieve pain of stable angina?

by reducing cardiac oxygen demand. 

First, relax peripheral arterioles, and thereby decrease afterload.  Second, verapamil and diltiazem reduce HR and contractility (in addition to decreasing afterload).

How do CCB's relieve variant angina pain?

by increasing cardiac oxygen supply; mechanism is relaxation of coronary artery spasm.

When a CCB and BB are combined, which drug is preferred and which is avoided and why?

Prefer a dihydropyridine (nifedipine)

Avoid verapamil and diltiazen because they intensify cardiosuppression caused by the BB, whereas a dihydropyridine will not.

How does Ranolazine reduce anginal pain?

By helping the heart generate energy more efficiently.

Is Ranolzaine used alone?

No.  Should be used with BB, Nitrate, or CCB amlodipine.

What is one serious cardiac risk with the use of Ranolozaine?

Increases QT interval and thereby poses the risk of torsades de pointes, a serious ventricular dysrythmmia.

What are the 2 objectives wtih patients who have

chronic stable angina?

1.  Prevention of MI and death

2.  Prevention of anginal pain.

What 2 drugs can lower the risk of MI and death?

1.  Antiplatelet agents (asa, clopidogrel)

2.  Cholesterol Lowering Drugs.

How is anginal pain prevented?

With one ore more long-acting antianginal drugs (BB, CCB, long-acting nitrate) supplemented with SL NTG when breakthrough pain occurs.