Antianginal Drugs - Ch 54 Flashcards
What is Angina?
-Chest pain
Supply of oxygen and nutrients in the blood is insufficient to meet demands of heart causing pain
What are the types of angina?
Stable (angina pectoris)
Unstable
Variant/Prinzmetal’s
Microvascular
What is stable angina?
Predictable
e.g, excercise, excitement
What is unstable angina?
Occurs without activity
What is Variant/Prinzmetal’s angina?
Coronary artery vasospasm
What is microvascular angina?
Spasms in smallest coronary arteries
Longer lasting pain (>10min to 30 min)
More common in women
What are the therapeutic goals of antianginal drugs?
Relieve pain of attack
Prevent angina (limit number of attacks)
What are the broad treatment goals of antianginal drugs?
- Improve blood flow in coronary circulation
- Reduce heart muscle metabolic demands
- or both
What are the kinds of antianginal drugs?
Organic Nitrates
Beta-blockers
Calcium channel blockers
Ranolazine
Examples of antianginal drug combinations?
Nitrates + CCBs
Nitrates + beta-blockers
CCBs + Beta-blockers
Nitrates + CCBs + Beta-Blockers
What are the avaialble forms of organic nitrates?
Sublingual
Oral capsules/tablets
IV solutions
Ointments
Transdermal patches
Translingual sprays
What do organic nitrates cause?
Vasodilation
-Relaxes vascular smooth muscle
When coronary arteries dilate due to organic nitrates what happens?
Increased coronary blood flow which is useful in variant angina
What happens when veins and systemic arteries relax due to organic nitrates?
Relaxed veins = Reduced cardiac preload
Relaxed systemic arteries = reduced cardiac afterload
What is preload?
Stress on ventricular wall before systole
Volume of blood in ventricles at the end of diastole/before systole (Frank-starling law)
What is afterload?
Resistance the heart has to pump against tat is determined by arteriolar pressure
Decreased preload caused by organic nitrates does what?
Dilate veins which decreases stroke volume, cardiac output and BP
= decreased cardiac work
Decreased afterload caused by organic nitrates does what?
Dilate arterties, decreases total peripheral resistance which decreases BP
= decreased cardiac work
Examples of organic nitrate?
Nitroglycerin
Isosorbide mononitrate
Isosorbide dinitrate
Nitroglycerin has a large what?
Large first-pass effect
How is nitroglycerin administered for symptomatic treatment?
Sublingual, not PO
How is nitroglycerin administered for angina prevention?
Patch or PO
When is IV nitroglycerin used?
BP control in perioperative hypertension, heart failure, ischemic pain, pulmonary edema due to acute MI and hypertensive emergencies
Prolonged action of isosorbide mononitrate is used for?
Prophylaxis
How is isosorbide mononitrate administered?
PO
-Has high bioavailability
Organic nitrate SL tablet or spray is used for?
Acute relief of angina (few min, lasts ~ 1 hour)
Organic nitrate Sl or oral is used for?
Prophylaxis in situations that may provoke angina like excercise
Transdermal patches (nitroglycerin) or oral (nitroglycerin, isosorbide mononitrate) is used for?
Long-term prophylaxis of angina
What adverse effects are associated with organic nitrates?
Headaches
Postural hypotension
Peripheral edema
Reflex tachycardia
headaches in patients taking nitrates are what?
Classic and predictable
Usually diminish in intensity/frequency with continued use
What does reflex tachycardia do?
Partially offsets beneficial effects
May combine with beta-blocker
What can develop quickly (over a single day) in patients taking oragnic nitrates?
Tolerance to the drug
What should the nurse teach the client is they are taking SL nitroglycerin?
Never to chew or swallow sublingual form
What should the nurse do when providing nitrate topical ointments or transdermal forms?
Rotate sites
Remove old mediaction
-remove topical forms at bedtime, apply new dose in the morning = reduce tolerance
-allow for a nitrate-free period
Examples of beta-blockers?
Atenolol
Metoprolol (Lopressor)
Propanolol (Inderal)
What is the mechanism of action of beta-blockers?
Decrease heart rate = decrease cardiac work
Decrease myocardiac contractility = decreased cardiac work
=Decreases myocardiac oxygen demand
What are beta-blockers used for?
Long-term prevention of angina
-Not for acute exacerbations of angina
Antihypertensive
Cardioprottective effects after MI
Migraines (propanolol)
Adverse effects of beta-blockers?
Bradycardia, hypotension, HF
Altered glucose and lipid metabolism
Dizzininess, fatigue, letahrgy, weird dreams
Impotence, wheezing, dyspnea
What should clients taking beta-blockers monitor daily?
Pulse rate
Report any pulse lower than 60 bpm
Why should beta-blocker use never be abruptly discontinued?
Rebound hypertensive crisis
Examples of CCBs?
Diltiazem (cardizem)
Verapamil
Nifedipine (other DHPs)
What is the mechanism of action of CCBs?
Reduce myocardial contractility (negative inotropic action)
cause peripheral arterial vasodilation
Decreased myocardial oxygen demand
What CCBs reduce myocardial contractility (negative inotropic action)?
Verapamil and diltiazem
What CCBs cause peripheral arterial vasodilation?
All CCBs
What drugs are first-line agents for treatment of angina, hypertension and supraventricular tachycardia?
Calcium channel blockers
What should clients taking antianginal drugs avoid?
Consuming alcohol
Going in hot baths, showers, hot tubs and saunas
(they cause vasodilation and hypotension)
Nurses should encourage clients to keep a record of what?
Their anginal attacks
-precipitating factors
-Numbers of pills taken
-Therapeutic effects
What should clients taking CCBs do to avoid constipation?
Adequate fluids and eat high-fibre foods
