Page 26 - pharma 1 theoretical updated MNU_Neat

Clinical pharmacy 2024/2025 Level 3 Pharm D Pharmacology 1 (PO 502)

2. Norepinephrine:

Receptor Acts mainly on -receptors with minor or no effect on -receptors

 both systolic and diastolic blood pressure,  mean pressure
(bradycardia): reflex mechanism to decrease heart rate → can be
Effect blocked by atropine

Cardiac output  and peripheral resistance 
No reversal effect of E on blood pressure
The main effect is vasoconstriction → used to increase blood pressure In
Use
Hypotensive state
S/E Vasospasm with tissue necrosis and gangrene at site of injection

Pheochromocytoma:

Diagnosis:
Chemically: not accurate. Pharmacologically
Determination of  By agents that promote the secretion of catecholamine

normetanephrine, E, NE from the tumor ➔ act on  ➔ increase BP” a histamine,
or VMA (vinyl mandelic methacholine
acid) in a 24-hr. urine  or by agents that inhibit action of NE and decrease blood

pressure e.g. phenoxybenzamine & phentolamine

 phenoxybenzamine & phentolamine used in diagnosis & treatment of
pheochromocytoma

3. Isoproterenol=Isoprenaline

Selectivity Stimulates β- receptors, no α action.

✓ +ve inotropic & chronotropic effects and increase cardiac output.
✓ Blood pressure remains constant at therapeutic doses, but in large
main effect doses blood pressure decreases

✓ Peripheral resistance decreases due to increase in flow and
decrease in pressure

Bronchodilation, used in bronchial asthma, also in complete heart
Uses
block.
Contra-
like E except hypertension.
indication

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