PHRM 825: Antiadrenergic Drugs Flashcards
1
Q
Phenoxybenzamine
A
- Non-selective alpha receptor antagonist (a1 and a2)
- Also blocks Ach, Histamine, and serotonin receptors
- Irreversible antagonist resulting from covalent modification of receptor
2
Q
Phentolamine
A
- Non-selective alpha receptor antagonist (a1 and a2)
- Competitive (reversible) blocker
- Potent vasodilator, but induces pronounced reflex tachycardia
- Blocks of presynaptic alpha 2 receptors may promote release of NE
- Also blocks 5-HT receptors, and is a muscarinic and histamine receptor agonist
3
Q
Prazosin
A
- alpha 1 adrenergic receptor antagonist
- Half-life: 3 hours
- “Quinazoline”
- Undergo extensive metabolism, excreted mainly in the bile
- Vasodilators
- Relaxation of smooth muscle in enlarged prostate and in bladder base
- “First-dose” effect
4
Q
Terazosin
A
- alpha 1 adrenergic receptor antagonist
- Half-life: 12 hours
- “Quinazoline”
- Undergo extensive metabolism, excreted mainly in the bile
- Vasodilators
- Relaxation of smooth muscle in enlarged prostate and in bladder base
- “First-dose” effect
5
Q
Doxazosin
A
- alpha 1 adrenergic receptor antagonist
- Half-life: 20 hours
- “Quinazoline”
- Undergo extensive metabolism, excreted mainly in the bile
- Vasodilators
- Relaxation of smooth muscle in enlarged prostate and in bladder base
- “First-dose” effect
6
Q
Yohimbine
A
- alpha 2 adrenergic receptor antagonist
- Indole alkaloid
- Found in Rubaceae and related trees. Also in Rauwolfia Serpentina
- Blockade of alpha 2 receptor increases sympathetic discharge
- Folklore suggests use in the treatment of male impotence
7
Q
Propranolol
A
- Non-selective beta-adrenergic receptor antagonist
- Lipophilic
- Local anesthetic properties
- Blockade is activity-dependent
8
Q
Pharmacologic effects of all beta-adrenergic receptor antagonists
A
- Decreased cardiac output
- Reduced renin release
- Increase VLDL, decrease HDL
- Inhibit lipolysis
- Inhibit compensatory glycogenolysis and glucose release in response to hypoglycemia
- Increase bronchial airway resistance
9
Q
What are therapeutic uses for beta-adrenergic receptor antagonists?
A
- Hypertension
- Angina
- Cardiac arrhythmias
- Migraine
- Stage fright
- Thyrotoxicosis
- Glaucoma
- Congestive heart failure (types II and III)
10
Q
Nadolol
A
- Non-selective beta-adrenergic receptor antagonists
- Less lipophilic than propranolol
- Long half-life: ~20 hours
- Mostly excreted unchanged in urine (not metabolized)
- Administration: Oral
- Uses: Hypertension, angina, migraine
11
Q
Timolol
A
- Non-selective beta-adrenergic receptor antagonist
- Thiadiazole nucleus with morpholine ring
- Administration: Oral, ophthalmic
- Uses: Hypertension, angina, migraine, glaucoma
12
Q
How do beta blockers affect pupil size?
A
They don’t. There are no beta receptors in the eye
13
Q
Pindolol
A
- Non-selective beta-adrenergic receptor antagonist
- Possesses “intrinsic sympathomimetic activity” (ISA)
- Partial agonist
- Less likely to cause bradycardia and lipid abnormalities
- Administration: Oral
- Uses: Hypertension, angina, migraine
14
Q
Carteolol
A
- Non-selective beta-adrenergic receptor antagonist
- Possess “intrinsic sympathomimetic activity” (ISA)
- Partial agonist
- Less likely to cause bradycardia and lipid abnormalities
- Administration: Oral, Ophthalmic
- Uses: Hypertension, glaucoma
15
Q
Metoprolol
A
- Selective beta 1-adrenergic receptor antagonist
- “Cardio-selective”
- Less bronchoconstriction
- Moderate lipophilicity
- Half-life: 3-4 hours
- Significant first-pass metabolism
- Administration: Oral, parenteral
- Uses: Hypertension, angina, antiarrhythmic, congestive heart failure
