ADRENOCEPTOR BLOCKERS Flashcards Preview

► Med Misc 05 > ADRENOCEPTOR BLOCKERS > Flashcards

Flashcards in ADRENOCEPTOR BLOCKERS Deck (29):
1

ALPHA BLOCKING DRUGS
All active by

 Oral route
 Parenteral route

2

IRREVERSIBLE LONG-ACTING

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

PHENOXYBENZAMINE

3

IRREVERSIBLE LONG-ACTING

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

PHENOXYBENZAMINE

4

REVERSIBLE SHORT-ACTING

 Prototype
 Nonselective (alpha1=alpha2)

PHENTOLAMINE

5

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

2-4 hours oral
20-40 minutes IV

6

ALPHA1 SELECTIVE

 Prototype
 Selective reversible alpha1 blocker

PRAZOSIN

7

PRAZOSIN
 Duration of action ---- hours

8-24

8


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

YOHIMBINE, RAUWOLSCINE

9


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

NONSELECTIVE BLOCKERS

10

EFFECTS
NONSELECTIVE BLOCKERS

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

11


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

EPINEPHRINE REVERSAL

12

EFFECTS
NONSELECTIVE BLOCKERS

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

EPINEPHRINE REVERSAL

13

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

SELECTIVE ALPHA1 BLOCKERS

14

CLINICAL USES

 Limited clinical application
 Presurgical treatment of pheochromocytoma

NONSELECTIVE ALPHA BLOCKERS

15

NONSELECTIVE ALPHA BLOCKERS
----- is used during the preparatory phase

Phenoxybenzamine

16

NONSELECTIVE ALPHA BLOCKERS
----- is used during surgery

Phentolamine

17

SELECTIVE ALPHA BLOCKERS
---- are used in hypertension

Prazosin, doxazosin, and terazosin

18


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

SELECTIVE ALPHA BLOCKERS

19

TOXICITY
Main manifestation is

orthostatic hypotension

20


 Competitive pharmacologic antagonists
 Developed for chronic oral use

BETA BLOCKING DRUGS

21

prototype of beta blocking drugs

Propranolol

22

BETA BLOCKING DRUGS

 Short-acting ester
 Used only parenterally

ESMOLOL

23

BETA BLOCKING DRUGS

 Longest acting beta-blocker

NADOLOL

24

BETA BLOCKING DRUGS

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

ACEBUTOLOL, ATENOLOL and NADOLOL

25

BETA BLOCKING DRUGS EFFECTS
1. CVS

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

26

BETA BLOCKING DRUGS EFFECTS
2. RESPIRATORY

 Bronchoconstriction
 Increase airway resistance

27

BETA BLOCKING DRUGS EFFECTS
3. EYE

 Decrease intraocular pressure
 Decrease production of aqueous humor

28

BETA BLOCKING DRUGS EFFECTS
4. METABOLIC AND ENDOCRINE

 Reduce insulin secretion
 Caution for insulin dependent DM

29

BETA BLOCKING DRUGS
CLINICAL USES

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

Decks in ► Med Misc 05 Class (295):