(Beta) b-Blockers :(Beta) b-Blockers atenolol (Tenormin)
metoprolol (Lopressor)
propranolol (Inderal)
nadolol (Corgard) 1
b-Blockers :b-Blockers Mechanism of action
b1-receptors on the heart are blocked
Decrease the HR, resulting in decreased myocardial oxygen demand and increased oxygen delivery to the heart
Decrease myocardial contractility, helping to conserve energy or decrease demand After an MI, a high level of circulating catecholamines irritate the heart, causing an imbalance in supply and demand ratio and even leading to life-threatening dysrhythmias. b-blockers block the harmful effects of catecholamines, thus improving survival after an MI 2
b-Blockers :b-Blockers Indications
Angina
Antihypertensive
Cardiac dysrhythmias
Cardioprotective effects, especially after MI
Some used for migraine headaches, essential tremors, and stage fright Adverse effects
Bradycardia, hypotension, second- or third-degree heart block
Altered glucose and lipid metabolism
Dizziness, fatigue, mental depression, lethargy, drowsiness, unusual dreams
Impotence, wheezing, dyspnea 3
Nursing Implications for b-Blockers :Nursing Implications for b-Blockers Patients taking b-blockers should monitor pulse rate daily and report any rate lower than 60 beats per minute
Dizziness or fainting should also be reported
Constipation is a common problem; instruct patients to take in adequate fluids and eat high-fiber foods These medications should never be abruptly discontinued due to risk of rebound hypertensive crisis
Inform patients that these medications are for long-term prevention of angina, not for immediate relief 4
Calcium Channel Blockers :Calcium Channel Blockers verapamil (Calan, Isoptin)
diltiazem (Cardizem)
nifedipine (Procardia)
amlodipine (Norvasc)
Many others 5
Calcium Channel Blockers :Calcium Channel Blockers Mechanism of action
Cause coronary artery vasodilation
Cause peripheral arterial vasodilation, decreasing systemic vascular resistance
Reduce the workload of the heart
Result: decreased myocardial oxygen demand Indications
First-line drugs for treatment of angina, hypertension, and supraventricular tachycardia
Coronary artery spasms (Prinzmetal’s angina)
Short-term management of atrial fibrillation and flutter
Several other uses 6
Calcium Channel Blockers :Calcium Channel Blockers Adverse effects
Very acceptable adverse effect and safety profile
May cause hypotension, palpitations, tachycardia or bradycardia, constipation, nausea, dyspnea (other adverse effects possible) Nursing Implications
Before administering, perform a complete health history to determine presence of conditions that may be contraindications for use or call for cautious use
Obtain baseline VS, including respiratory patterns and rate
Assess for drug interactions 7
Calcium Channel Blockers: Nursing Implications :Calcium Channel Blockers: Nursing Implications Patients should not take any medications, including OTC medications, without checking with the physician
Patients should be encouraged to limit caffeine intake Patients should report blurred vision, persistent headache, dry mouth, dizziness, edema, fainting episodes, weight gain of 2 pounds in 1 day or 5 or more pounds in 1 week, pulse rates less than 60, and any dyspnea 8
Calcium Channel Blockers: Nursing Implications :Calcium Channel Blockers: Nursing Implications Constipation is a common problem; instruct patients to take in adequate fluids and eat high-fiber foods 9
Antianginal Drugs: Nursing Implications :Antianginal Drugs: Nursing Implications Monitor for adverse reactions
Allergic reactions, headache, lightheadedness, hypotension, dizziness
Monitor for therapeutic effects
Relief of angina, decreased BP, or both 10