This document summarizes the mechanisms and effects of several antihypertensive drugs: Reserpine, Guanethidine, Bretylium. Reserpine blocks vesicular monoamine transporters to inhibit neurotransmitter release from vesicles. Guanethidine and Bretylium inhibit nerve impulse-coupled neurotransmitter release from vesicles and displace neurotransmitters from storage vesicles. The document then outlines the effects of these drugs in various organ systems and potential side effects.

1. Presentation by
Shahan ullah
Assigned by
Dr. Niaz Ali

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. AntiHypertensive
RESERPINE
AntiPsychotic
Antiemetic

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. .
Biphasic
response
Triphasic
response
Monophasic
response
Lowering
of BP

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
