B-Adrenergic Antagonist

Question 1

Propranolol (Inderal)

Answer 1

Prototype B-blocker

Non-selective (blocks both B1 and B2 receptors)

Used for: HTN, ‘speakers’ nerves, angina, arrhythmias, migraines, pheochromocytoma

Has membrane stabilizing effect (LA), which enhances its anti-arrythmic effects (most B-blockers share this property)

Contraindicated in shock, bradycardia, asthma, CHF

Side Effects: bradycardia, CHF, hypotension, heart block, insomnia, hallucinations, bronchospasms

Question 2

Nadolol (Corgard)

Answer 2

Non-selective B antagonist
Used for: treating angina, HTN
Contraindicated in bradycardia, bronchial asthma, shock, heart block, myocardial infarction (?)
Side Effects: bradycardia, cardiac failure, conduction disturbances, arrhythmias, dizziness, bronchospasm, diarrhea, impotence, decreased libido, blurred vision

Question 3

Timolol (TImoptic)

Answer 3

Non-selective B antagonist
Used for: treating HTN, ocular HTN (wide angle glaucoma)
Contraindications: asthma, COPD, bradycardia, HF
Side Effects: fatigue, dizziness, cold hands and feet

Question 4

Pindolol

Answer 4

Non-selective B-antagonist with some sympathetic agonist activity
A vasodilatory B-blocker (due to strong B2 agonist activity)
Also not as much bronchoconstriction as with other B2-blockers
Used for: HTN
Contraindications: bradycardia, COPD, HF
Side Effects: fatigue, dizziness, diarrhea, cardiac failure

Question 5

Labetalol HCl

Answer 5

a1, B1, and B2 antagonist (non-selective)
Partial agonist at some B2 receptors
Used for: HTN
Contraindications: asthma, cardiac failure, severe bradycardia
Side Effects: postural hypotension, sweating, dizziness, N/V, nasal stuffiness, bradycardia, impotence

Question 6

Carvedilol (Coreg)

Answer 6

a1, B1, and B2 antagonist
Higher B:a blockade than Labetolol (and longer duration)
Used for: angina, HF (NYHA type II and III), HTN
Contraindications: bronchospasm, emphysema, COPD, asthma, bradycardia, DM, HF (NYHA type IV), liver disease, pheochromocytoma
Adverse Reactions: Bronchospasm, diarrhea, dyspnea, fatigue, headaches, hypotension, peripheral edema, bradycardia, syncope

Question 7

Metoprolol (Lopressor)

Answer 7

B1 antagonist
Used for: HTN and angina pectoris
Contraindications: bradycardia, heart block, shock, MI (?)
Side Effects: dizziness, bradycardia, nightmares, CHF, peripheral edema, bronchospasms, nausea, diarrhea

Question 8

Acebutolol (Sectral)

Answer 8

Mostly B1 blockade, but is also a partial sympathetic agonist (non-selective)
Low lipid solubility, so little CNS side effects
Membrane stabilizing effect on the action potential is present, but less than Propranolol
Used for: HTN and to control ventricular arrhythmias
Does not cause as much bronchoconstriction as non-selective B-blockers
Less likely to cause bradycardia than other B1 blockers, due to its intrinsic sympathomimetic activity
Side Effects: alopecia, dizziness, angina, fatigue, HF

Question 9

Atenolol (Tenormin)

Answer 9

Blocks B1 mostly
Used for: HTN, acute MI, angina pectoris
Contraindications: bradycardia, heart block, shock, cardiac failure
Adverse Reactions: bradycardia, dizziness, fatigue

Question 10

Esmolol (Brevibloc)

Answer 10

B1 antagonist
Given by IV infusion
Used for: atrial fibrillation or flutter, paroxysmal SVT
Contraindications: bronchospasms, bradycardia, shock
Side Effects: AV block, cardiac arrest, hypotension, bradycardia
Half-life of only a few minutes (very short duration)

Question 11

Metyrosine (Demser)

Answer 11

Inhibitor of tyrosine hydroxylase
Used for pheochromocytoma
Contraindications: hepatic disease, Parkinson’s disease
Adverse Reactions: anxiety, confusion, crystalluria, depression, Parkinsonism, salivation

Question 12

6-hydroxydopamine (experimental)

Answer 12

Taken up into adrenergic nerve terminals and destroys the cells
Stimulates free radical production in cells, leading to cell death
Therefore, removes adrenergic neurons (chemical sympathectomy)

Question 13

Bretylium Tosylate

Answer 13

Blocks catecholamine release from nerve terminal
Used for V-Tach, prophylaxis of ventricular fibrillation
Adverse Reactions: hypotension, bradycardia

Question 14

Reserpine (Serpalan)

Answer 14

Inhibits storage of catecholamines (and serotonin) in granules, leading to depletion
Initial effects may cause transient release
Used for: HTN, schizophrenia
Contraindications: mental depression, peptic ulcer, ulcerative colitis
Side Effects: vomiting, diarrhea, dry mouth, syncope, angina, many more