PHARM Chapter 18

Adrenergic Antagonists

adrenergic antagonists cause direct blockade of adrenergic receptors. With one exception, all adrenergic antagonists produce reversible (competitive) blockade
unlike many adrenergic agonists which act at alpha and beta adrenergic receptors, most adrenergi

Alpha Adrenergic Antagonists blockade

THERAPEUTIC RESPONSES
-most of the clinically useful responses to alpha-adrenergic antagonists result from blockade of alpha1 receptors in the blood vessels.
*essential hypertension- high BP can be treated with a variety of drugs, including alpha-adrenerg

Alpha Adrenergic Antagonists drugs

Only 7 alpha adrenergic antagonists are employed clinically. Because the alpha blockers often cause postural hypotension, therapeutic uses are limited.
2 groups- (1) NONSELECTIVE drugs that block alpha 1 and alpha 2 (2) SELECTIVE drugs that block alpha 1

Beta-Adrenergic Antagonist Blockade

Practically all of the therapeutic effects of the beta-adrenergic antagonists result from blockade of beta1 receptors in the heart.
The major consequences of blocking these receptors are (1) reduced heart rate (2) reduced force of contraction (3) reduced

Beta Androgenic Antagonist Drugs

3 groups.
(1) First generation (nonselective) beta blockers which block beta1 and beta2 PROPANOLOL
(2) second-generation (cardioselective) beta blcokers which produce selective blockade of beta 1 receptors (at usual doses) METROPROLOL
(3) third-generation

Propanolol

First generation (nonselective) beta blockers which blocks both beta1 and beta2.
Was the first beta blocker to receive widespread clinical use and remains one of our most important beta-blocking agents.
PHARMACOLOGIC EFFECTS-
*by blocking cardiac beta1 re

Metoprolol

a second-generation (cardioselective) beta blcokers which produce selective blockade of beta 1 receptors (at usual doses)
At usual therapeutic doses the drug does not caused beta2 blockade. At higher doses it can.
because their effects on beta 2 are minim

Receptor Specificity BB

with regard to receptor specificity, beta blockers fall into 2 groups: nonselective & cardioselective.
non-selective agents block beta1 and beta2 receptors whereas cardioselective agents block beta1 receptors (at usual doses)
because of their limited side

Pharmacokinetics BB

The relative lipid-solubility of these agents is of particular importance.
Drugs with high solubility have two prominent features (1) penetrate the blood brain barrier with ease (2) they are eliminated primarily by hepatic metabolism.
Conversely drugs wit

Therapeutic Uses BB

Principal indications for beta-adrenergic blockers are hypertension, angina pectoris, and cardiac dysrhythmias.
Other uses include prophylaxis of migraine headache, treatment of myocardial infarction, symptom supression in individuals with situational anx

Adverse Effects

by blocking beta1 receptors in the heart all of the beata blockers can cause bradycardia, AV heart block, and rarely Heart failure.
By blocking beta2 receptors in the lungs nonselective agents can cause significant bronchoconstriction in patients with ast