Adrenergic Antagonists

Question 1

Clinical uses of Alpha Adrenergic Antagonists

Answer 1

Pheochromocytoma
Hypertension
Urinary Obstruction (BPH)
Depression

Question 2

Phenoxybenzamine Uses

Answer 2

Pheochromocytoma (Tumor of the adrenal medulla that secretes catecholamines)
=Binds covalently (irreversibly) to a1- and a2-receptors and inhibits reuptake.

Question 3

Phentolamine Uses

Answer 3

Pheochromocytoma

=Binds reversibly to a1 and a2 receptors.

Question 4

Prazosin, Terazosin, Doxazosin

Uses

Answer 4

Selective α-1 Antagonists

Used in Hypertension and Benign Prostate Hyperplasia (BPH), Hypertension, and Urinary Obstruction

Question 5

Mirtazapine Uses

Answer 5

Selective α-2 Antagonist
=Used as an antidepressant
Blocks presynaptic α-2 receptors in the CNS (facilitates the release of norepinephrine)

Question 6

Clinical uses of Beta Antagonists (β-Blockers)

Answer 6

Hypertension
Ischemic Heart Disease
Cardiac Arrhymias
Heart Failure
Other Cardiovascular Disorders
Glaucoma
Hyperthyroidism
Neurologic Disorders

Question 7

Non-selective β-Blocker (β-1 and β-2)

Answer 7

Propranolol
Nadolol
Pindolol
Timolol (glaucoma)

Question 8

Cardio-selective β-Blocker (β-1)

Answer 8

Metoprolol
Atenolol
*Useful in patients who show bronconstriction with propranolol but not selective enough to be used safely in asthma patients

Question 9

LabetAlol

Answer 9

β-1, β-2 and α-1 blockers
Used in hypertension
Doesn’t usually cause hypotension in healthy individuals with normal blood pressure

Question 10

β-Blockers Used for Ischemic Heart Disease

Answer 10

• reduce the frequency of anginal
• improve exercise tolerance
• decrease cardiac work & reduce oxygen demand
• indicated in the acute phase of a myocardial infarction

Question 11

β-Blockers Used for Glaucoma

Answer 11

Timolol- lack local anesthetic properties and are suitable for use in the eye
*Sufficient timolol may be absorbed to cause serious adverse effects on the heart and airways in susceptible individuals

Question 12

β-Blockers Used for Hyperthyroidism

Answer 12

Propanolol used in patients with “Thyroid Storm” (severe hyperthyroidism & Grave’s Disease) to control supraventricular tachycardia

Question 13

β-Blockers Used for Neurologic Disorders

Answer 13

• reduce frequency & intensity of migraine headache
• reduce certain tremors
• reduce performance anxiety (“stage fright”) e.g. Propranolol

Question 14

CNS Effects of β-Blockers

Answer 14

• Mild sedation, vivid dreams, and rarely, depression
• β-Blockers with low lipid solubility (nadolol or atenolol) may cause a lower incidence of CNS adverse effects than those with higher lipid solubility