Adrenergic Neuroblockers, Mechanism of Action, Indications, Side Effects, Contra Indications

1. Shahan Ullah
MPhil Pharmacology
Institute of Basic Medical Sciences
Khyber Medical University Peshawar

2. Reserpine Guanethidine Bretylium

4.  RESERPINE
 It blocks the Mg/ATP dependent VESICULAR
MANO AMINE TRANSPORTER(VMAT)
 GUANATHEDINE/BRETYLIUM
 It inhibits nerve impulse coupled N.A release
from vesicles(bretylium).
 Displaces N.A from storage vesicles
 Engages and blocks the N.A reuptake at
axonal membrane.(REUPTAKE 1)

5. ORGAN/SITE ACTION
CENTRAL NERVOUS YSTEM ↓ dopamine
↓ serotonin
↓ nor adrenaline
CARDIOVASCULAR SYSTEM ↓ cardiac output
↓ vascular resistance
GIT Ultimate increase motility
Ultimate increased secretions
Reproductive system Decrease in libido
Nasal region Turbinate lateral wall size
increase
Eye Dilator pupillae are blocked
Metabolism Anti diabetogenic

6. RESERPINE
Anti-
Hypertensive
Anti-
Emetic
Anti-
Psychotic

7. Organ/site Effect
CENTRAL NERVOUS SYSTEM DEPRESSION (suicidal tendency)
NIGHTMARES
EXTRA PYRAMIDAL (PARKINSON)
EFFECTS
CARDIOVASCULAR SYSTEM MILD POSTURAL HYPOTENSION
GIT DIARRHOEA
ACIDITY
NASAL REGION NASAL CONGESTION
REPRODUCTIVE SYSTEM DELAYED EJACULATION

8. PEPTIC ULCER
DEPRESSION

9. .
Lowering
of BP
Triphasic
response
Biphasic
response
Monophasic
response

10. ORGAN/SITE ACTION
CENTRAL NEROUS SYSTEM DOESN’T CROSS BBB
RENAL ↓INITIAL BLOOD FLOW,
(regulatory action)
GASTRO INTESTINAL TRACT INCREASE MOTILITY(PSNS)
INCREASE SECRETIONS(PSNS)
EYE DECREASE I.O.T
MIOSIS
NASAL REGION INCREASE SIZE OF TURBINATE
LATERAL WALLS (INCREASE
CORONARY FLOW)

11.  Postural hypotension
 Weakness
 Diarrhoea
 Delayed or retrograde ejaculation
 Nasal stuffiness
 It cause super sensitivity of receptors leading
to regulation of α1 receptors causing intense
vasoconstriction (HTN crisis)
 Fluid retention (long term use tolerance
develops)
 Worsening of CCF.

12.  ANTI HYPERTENSIVE(Last choice therapy)
 For management of Pheochromocytoma

13.  ACTIVITY
 Prolongs duration of ventricular action potential
 It prolongs the refractory period of ischemic
heart tissue and decreases its excitability(by
blocking K+ channels)
 Also blocks N.A release.
 THERAPEUTIC USE
 Anti- arrhythmic
 Anti-hypertensive
 ADVERSE EFFECTS
 Postural hypotension
 Bradycardia
 Nausea/Vomiting