ADRENOCEPTOR BLOCKERS

Question 1

ALPHA BLOCKING DRUGS

All active by

Answer 1

 Oral route

 Parenteral route

Question 2

IRREVERSIBLE LONG-ACTING

 Prototype
 Only slightly alpha1 selective
 Short elimination half life

Answer 2

PHENOXYBENZAMINE

Question 3

IRREVERSIBLE LONG-ACTING

 Long duration of action (48 hours)
 Binds covalently to its receptors

Answer 3

PHENOXYBENZAMINE

Question 4

REVERSIBLE SHORT-ACTING

 Prototype
 Nonselective (alpha1=alpha2)

Answer 4

PHENTOLAMINE

Question 5

PHENTOLAMINE
 Duration of action
 Oral ( —- hours)
 IV ( —– minutes)

Answer 5

2-4 hours oral

20-40 minutes IV

Question 6

ALPHA1 SELECTIVE

 Prototype
 Selective reversible alpha1 blocker

Answer 6

PRAZOSIN

Question 7

PRAZOSIN

 Duration of action —- hours

Answer 7

8-24

Question 8

 Prototype
 Selective alpha2 competitive blockers
 Used primarily in research application

Answer 8

YOHIMBINE, RAUWOLSCINE

Question 9

 Most important effects are on the CVS system
 Reduction in cardiovascular tone
 Reduction of both arterial and venous
pressure (decrease in BP)

Answer 9

NONSELECTIVE BLOCKERS

Question 10

EFFECTS

NONSELECTIVE BLOCKERS

Answer 10

-Cause baroreceptor reflex-mediated
tachycardia as a result of the drop
in mean arterial pressure (MAP)
-Tachycardia maybe exaggerated

Question 11

 Predictable result of the use of an
agonist in a patient who has received
an alpha-blocker

Answer 11

EPINEPHRINE REVERSAL

Question 12

EFFECTS
NONSELECTIVE BLOCKERS

 Not observed with phenylephrine
or NE because they lack sufficient
beta2 effects

Answer 12

EPINEPHRINE REVERSAL

Question 13

Block alpha1 receptors much more effectively
Cause much less tachycardia than
the nonselective blockers when
reducing BP

Answer 13

SELECTIVE ALPHA1 BLOCKERS

Question 14

CLINICAL USES

 Limited clinical application
 Presurgical treatment of pheochromocytoma

Answer 14

NONSELECTIVE ALPHA BLOCKERS

Question 15

NONSELECTIVE ALPHA BLOCKERS

—– is used during the preparatory phase

Answer 15

Phenoxybenzamine

Question 16

NONSELECTIVE ALPHA BLOCKERS

—– is used during surgery

Answer 16

Phentolamine

Question 17

SELECTIVE ALPHA BLOCKERS

—- are used in hypertension

Answer 17

Prazosin, doxazosin, and terazosin

Question 18

 Used together with tamsulosin for urinary hesitancy and prevention of urinary retention with benign prostatic hyperplasia

Answer 18

SELECTIVE ALPHA BLOCKERS

Question 19

TOXICITY

Main manifestation is

Answer 19

orthostatic hypotension

Question 20

 Competitive pharmacologic antagonists

 Developed for chronic oral use

Answer 20

BETA BLOCKING DRUGS

Question 21

prototype of beta blocking drugs

Answer 21

Propranolol

Question 22

BETA BLOCKING DRUGS

 Short-acting ester
 Used only parenterally

Answer 22

ESMOLOL

Question 23

BETA BLOCKING DRUGS

 Longest acting beta-blocker

Answer 23

NADOLOL

Question 24

BETA BLOCKING DRUGS

 Less lipid soluble
 Enter the CNS to a lesser extent

Answer 24

ACEBUTOLOL, ATENOLOL and NADOLOL

Question 25

BETA BLOCKING DRUGS EFFECTS

1. CVS

Answer 25

 Decrease BP
 Antagonize renin secretion
 (-) inotropic effect
 (-) chronotropic effect

Question 26

BETA BLOCKING DRUGS EFFECTS

2. RESPIRATORY

Answer 26

 Bronchoconstriction

 Increase airway resistance

Question 27

BETA BLOCKING DRUGS EFFECTS

3. EYE

Answer 27

 Decrease intraocular pressure

 Decrease production of aqueous humor

Question 28

BETA BLOCKING DRUGS EFFECTS

4. METABOLIC AND ENDOCRINE

Answer 28

 Reduce insulin secretion

 Caution for insulin dependent DM

Question 29

BETA BLOCKING DRUGS

CLINICAL USES

Answer 29

 Open-angle glaucoma
 Hypertension
 Angina
 Arrhythmias
 Chronic heart failure
 Pheochromocytoma