2. Presented by: Maqzia Mushtaq
Presented to: Sir Abdullah

3.  Beta receptors are membrane bound G protein
coupled receptors which function primarily by increasing
or decreasing intracellular production of second
messenger cAMP.

4.  3 types:
 Beta 1 receptors:
 Beta 2 receptors:
 Beta 3 receptors:
located on adipose
tissue.

6. “PROPRANOLOL”
 Pharmacokinetics:
• Well absorbed orally.
• Low bioavailibility due to high first pass metabolism
in liver.
• Lipophilic in nature so can penetrate into brain easily.
• Metabolism depend on hepatic blood flow.
• Bioavalability is increased when taken just after
meal.

7.  Pharmacological actions:
Cardiovascular system:
 Dec. heart rate-antianginal
 Dec. force of contraction-antihypertensive
 Membrane stabilizing action-antiarrhythmics
 Reduces ill influence of NA on heart-
cardioprotective.

8.  Blood vessels:
 Blocks vasodilation and fall in BP evoked by
isoprenaline.
 TPR initially increased (inhibition of vasodilation)-
little change in BP
 On continue treatment resistant vessels gradually
adopt to chronically reduced CO-TPR dec.
 Reduce NA release due to block of presynaptic
beta action
 Dec. renin release from kidney

9.  Respiratory system:
 Blocking beta 2 in broncial smooth muscle can
cause life threating broncho-constriction in
asthmatics.
 CNS:
 Beside decreasing central sympathetic outflow
causes sedation litharge disturbance in sleep after
long term use.
 Suppresses anxiety.

10.  Metabolic effects:
 In normal person it has min. effect on basal blood
glucose-long term use dec. insulin.
 Hyperlipidemia-inc. VLDL,TG,CH,LDL.
 Inhibits glycogenolysis in heart,skeletel muscle an in
liver
 Skeletal muscle:
 Inhibit adrenergically provoked tremor.
 Fatigue-reduce blood flow.
 Eye:
 Dec. secretion of aqueous humor-dec. IOT.

11.  Adverse effects:
 Bradycardia
 Plasma lipid is altered .
 Worsens in asthama.
 Impaired carbohydrate tolerance.
 HTN
 Angina-sudden death
 Cold extremities

12.  Drug interaction
 digitalis,verapamil causes additive depression of
SA node and AV conduction leading to cardic
arrest.
 Enzyme induces-phenytion,rifampicin, smoking
dec. its plasma conc.
 Cimetidine and hydralazine may increase its
bioavalibility.
 Warning signals of hypoglycemia mediated
through sympathatic stimulation is supressed-
hypoglucemic coma.

13.  More potent in blocking Beta 1- cardiac receptors.
 Pharmacokinetics:
 Completely absorbed orally.
 Do not cross BBB.
 Daily dose is sufficient because of longer duration
of action.
 Have low lipid solubility.

14.  Use:
 Atenolol is used in angina and the most
commonly used beta blocker for hypertension.

15.  Intravenous
It has been used to terminate:
 Peroximal supraventricular tachycardia.
 Episodic atrial fibrillation
 Adrenergically mediated arrhythmia
 Arrhythmia during anaesthesia.
 Intra operative,postoperative hypertension.
 In early treatment of myocardial infarction.

16.  Both alpha and beta blocker.
 Given as an I.V bolus or infusion in hypertensive
emergencies.
 Actions:
 reduce BP.
 Used in hypertensive emergency.
 Does not alter serum lipid/blood glucose level,
does not cause reflex tachycardia.
 Adverse effects:
 Orthostatic, hypotension ,dizziness

17.  Use in:
 Hypertension
 Angina pectoris
 Cardiac arrhythmias
 Myocardial infarction
 Congestive heart failure
 Pheochromocytoma
 Migraine
 Anxiety
 Glaucoma