Chap 23 Antianginal Drugs Flashcards
Angina Pectoris
Result of myocardial ischemia caused by imbalance between myocardial blood supply and oxygen demand
Angina or chest pain is common
Ischemia
Ischemia*
Poor blood supply to an organ
Ischemic heart disease*
Poor blood supply to the heart muscle
Atherosclerosis
Coronary artery disease
Myocardial infarction (MI)*
Necrosis, or death, of cardiac tissue
Disabling or fatal
Types of Angina
Stable Angina*
“effort angina” triggered by physical or mental exertion
resolves with rest or nitrates
Unstable Angina*
new onset or worsening angina - unpredictable
rest/meds do not resolve
acute coronary syndrome; may lead to MI
Vasospastic Angina*
aka, variant/prinzmetal
occurs spontaneously, often at rest, common at night/early morning, especially exercise
more common in women and smokers
responds to nitrates: CCBs suppress(beta blockers do not)
Microvascular Angina*
Angina due to coronary microvascular dysfunction or vasospasm
accounts or chest pain up to 50% of pts w/out obstructive epicardial CAD
can occur with exertion or at rest
may respond less with exertion or at rest
be difficult to distinguish from epicardial angina, diagnose with PET or CMR
Drugs for Angina
Nitrates* or nitrites*
Beta blockers*
Calcium channel blockers (CCBs)
Goal: to increase blood flow to the ischemic myocardium, decrease myocardial oxygen demand, or both
Nitrates and Nitrites Forms& exs.
Available forms
Sublingual*
Chewable tablets
Oral capsules/tablets
Intravenous (IV) solutions*
Transdermal patches*
Ointments
Translingual sprays*
*Bypass the liver and the first-pass effect.
Nitroglycerin (both rapid and long acting)
Isosorbide dinitrate* (both rapid and long acting)*
Isosorbide mononitrate* (primarily long acting)
Nitrates and Nitrites: Mechanism of Action and Drug Effects
Cause vasodilation* because of relaxation of smooth muscles
Potent dilatingeffect on coronary arteries
Result:* oxygen to ischemic myocardial tissue
Used for prevention and treatment of angina
Nitrates and Nitrites: Indications
Treat stable, unstable, and vasospastic angina
Rapid-acting forms
Used to treat acute* anginal attacks*
Sublingual tablets; IV infusion
Long-acting forms*
Used to PREVENT anginal episodes
Nitrates: Contraindications
Known drug allergy
Severe anemia
Closed-angle glaucoma
Hypotension
Severe head injury*
Use of the erectile dysfunction drugs sildenafil (Viagra), tadalafil* (Cialis), and vardenafil *(Levitra)
Nitrates Adverse Effects
mostly due to vasodilatation
most common is throbbing headache 60% of pts
postural hypotension*
facial flushing
tachycardia
Tolerance develops rapidly on continued use
most practical way prevent nitrate tolerance, provide nitrate free intervals everyday
interval typically 10-12 hrs at night cause decreased demand on heart
Nitrate Tolerance
Occurs in patients taking nitrates around the clock or with long-acting forms
Prevented by allowing a regular nitrate-free period to allow enzyme pathways to replenish
Transdermal forms: remove patch at bedtime for 8 hours, then apply a new patch in the morning
Nitroglycerin
Prototypical nitrate
important drug used in symptomatic treatment of ischemic heart conditions such as angina
Routes—PO, SL, metered-dose aerosol that is sprayed under the tongue, IV, and topical
Large first-pass* effect with oral* forms
Beta Blockers
Mainstay in the treatment of several cardiovascular diseases
Angina*
MI*
Hypertension*
Dysrhythmias *
Cardioselective Beta Blockers mnemonic
HINT: M—E
Metoprolol
Atenolol
Nebivolol
Bisoprolol
Acebutolol
Betaxolol
Esmolol
B1 = 1 Heart
B2 = 2 Lungs
Beta Blockers: Mechanism of Action
Block beta1 receptors on the heart
Decrease heart rate, resulting in decreased* myocardial oxygen demand* and increased* oxygen delivery to the heart*
Decrease myocardial contractility, helping to conserve energy or decrease demand
Beta Blockers: Indications
Angina*
Antihypertensive*
Cardiac dysrhythmias*
Cardioprotective* effects, especially after MI*
Some used for migraine* headaches, essential tremors, and stage fright
Beta Blockers Nursing Implications
Beta blockers*
Patients taking beta blockers should monitor* their pulse* rates daily* and report* any rate lower* than 60* beats/min or symptoms of relative bradycardia.
Instruct patients to report dizziness or fainting.
Inform patients that these medications should never be abruptly discontinued.
Inform patients that these medications are for long-term prevention of angina, not for immediate relief.
Beta Blockers: Contraindications
Systolic HF
Serious conduction disturbances
Caution: bronchial asthma because any level of blockade of beta2 receptors can promote bronchoconstriction
Diabetes mellitus: can mask hypoglycemia-induced tachycardia
Peripheral vascular disease: may further compromise cerebral or peripheral blood flow
Beta Blockers: Adverse Effects
Cardiovascular*
Bradycardia, hypotension, atrioventricular (AV) block
Metabolic*
Hyperglycemia, hypoglycemia, hyperlipidemia
Central nervous system
Dizziness, fatigue, depression, lethargy*
Other
Impotence*, wheezing, dyspnea
Atenolol (Tenormin)
Cardioselective beta1-adrenergic receptor blocker
Indication: prophylactic* treatment of angina pectoris*
Use of atenolol after MI has been shown to decrease mortality.
Metoprolol (Lopressor, Toprol-XL)
Cardioselective beta1-adrenergic receptor blocker
Indication: prophylactic treatment of angina
Many of the same characteristics as atenolol
Reduces mortality rate in patients after MI and in treating angina
Forms: oral (immediate release and long acting) and parenteral (injectable) forms
IV metoprolol is commonly administered to hospitalized patients after an MI and is used for treatment of hypertension in patients unable to take oral medicine.
CCBs for Chronic Stable Angina
Amlodipine*
Diltiazem (DILT)
Nicardipine
Nifedipine
Verapamil
CCBs: Mechanism of Action
Cause coronary artery vasodilation
Cause peripheral arterial vasodilation, thus decreasing systemic vascular resistance
Reduce the workload of the heart
Result: decreased myocardial oxygen demand
Dysrhythmias: depression of the automaticity of and conduction through the sinoatrial and AV nodes
Calcium Channel Blockers: Indications& Contraindications
Indications
Angina
Hypertension
Supraventricular tachycardia
Coronary artery spasms (Prinzmetal angina)
Short-term management of atrial fibrillation and flutter
Migraine headaches
Raynaud’s disease
Nimodipine: cerebral artery spasms associated with aneurysm rupture
Contraindications
Known drug allergy
Acute MI
Second- or third-degree AV block (unless the patient has a pacemaker)
Hypotension
Calcium Channel Blockers: Adverse Effects
Limited
Primarily relate to overexpression of their therapeutic effects
May cause hypotension, palpitations, tachycardia or bradycardia, constipation, nausea, dyspnea, other adverse effects
Constipation is a common problem; instruct patients to take in adequate fluids and eat high-fiber foods
Diltiazem* (Cardizem, Dilacor, Tiazac)
effective for the txt angina pectoris from coronary insufficiency and HTN
Used in txt of A-Fib/flutter with paroxysmal SVT
Amlodipine (Norvasc)
Indicated for both angina and hypertension
Available only for oral use
Nursing Implications
Patients should report:
Blurred vision*
Persistent* headache*
Dry mouth
Edema*
Fainting episodes
Weight* gain* of 2 lb in 1 day or 5 lb in 1 week
Pulse* rate less than 60 beats/min*
Dyspnea*
Alcohol and hot baths/whirlpools, hot tubs, or saunas result vasodilation, hypotension, possibility of fainting.
Teach change* positions* slowly* to avoid postural BP changes.
Encourage patients to keep a record of their anginal attacks, including precipitating factors, number of pills taken, and therapeutic effects.
Nitroglycerin Implications
Instruct patients in proper* technique* and guidelines for taking sublingual nitroglycerin for anginal pain.
Instruct patients never to chew or swallow the
sublingual* form.
Instruct patients that a burning sensation felt with sublingual forms indicates that the drug* is still potent.*
Instruct patients to keep a fresh* supply of sublingual medication on hand; potency* is lost in about 3* months after the bottle has been opened*
If anginal* pain occurs:*
Stop activity* and sit or lie down and take* a sublingual* tablet.
If there is no relief in 5 minutes, call 911* or emergency services immediately* and take* a second* sublingual tablet.
If there is no relief in 5 minutes, take a third* sublingual tablet.
Do not* try to drive* to the hospital.
IV forms of nitroglycerin must be given with special non-PVC tubing and bags.
Discard parenteral solution that is blue, green, or dark red.*
Follow specific manufacturer’s instructions for IV administration.
