Propranolol Pharmacology

Propranolol

About Propranolol
A synthetic non-selective beta blocker , Antiarrhythmic,antihypertensive,antianxiety,migraine prophylatic.
Mechanism of Action of Propranolol
Propranolol is a non selective beta receptor antagonist. It have negative chronotropic and negative inotropic effects on heart. It decreases oxygen consumption; cardiac work and aortic pressure It decreases nor adrenaline and renin releases. It decreases central sympathetic out flow.
In sympathetic over activity, it prolongs systole by retarding conduction. It increases oxygen supply and exercise tolerance in angina patients. It decrease automaticity and abbreviates refractory period of myocardial fibers and decreases rate of depolarization in SA node, Purkinje fibers, and other ectoptic foci. Prolong effective refractory period of AV node and AV conduction is delayed. At higher doses direct depressant membrane stabilizing action is exerted. The drug decreases BP in hypertensive individuals. Initially total peripheral resistance increases due to blockade of beta mediated vasodilatation and decrease in cardiac output; so little change in BP. But when treatment is continued due to adaptation of resistance vessels to decreased cardiac output total peripheral resistance decreases and systolic and diastolic BP falls.
Antimigraine action: Propranolol is useful in migraine due to its beta blockade action. Through beta blockade action it inhibits vasodilation and relieves migraine.
Pharmacokinets of Propranolol
Absorption: well absorbed orally, bioavailabity is increased by administering along with food.
Distribution: Widely distributed in a plasma protein bound form.
Metabolism: Metabolized in liver.
Excretion: Excreted through urine.

Onset of Action for Propranolol
N/A
Duration of Action for Propranolol
Up to 12 hours
Half Life of Propranolol
4 hours
Side Effects of Propranolol
1.Congestive heart failure is precipitated or aggravated
2.Decreases coronary blood flow
3.Forgetfulness
4.Nightmares
5.Decreases exercise capacity
6.Decreases carbohydrate tolerance
7.Decrease insulin release
8.Increases free fatty acid levels and increase LDL to HDL ratio
9.Worsens chronic obstructive lung diseases
10.Gastrointestinal problems
11.Nausea
12.Sexual dysfunction
13.Cold extremities
14.Tiredness
15.Exacerbates prinzmetal`s angina
16.Bradycardia
17.Depression
18.Fever
19.Rash

Contra-indications of Propranolol
1.Hypersensitivity to the drug
2.Second or third degree heart block
3.Congestive heart failure
4.Cardiogenic shock
5.Bradycardia
6.Chronic obstructive pulmonary diseases
7.Hypoglycemia
8.Haemorrhage

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Special Precautions while taking Propranolol
1.Peripheral arterial diseases
2.Ischaemic heart disease
3.Congestive heart failure
4.Renal impairment
5.Hepatic impairment
6. Diabetes mellitus
7. The drug should be gradually withdraw with caution
8. Non allergic bronchospastic diseases
9. Thyrotoxicosis
10. Along with other antihypertensive drugs

Pregnancy Related Information
Contraindicated
Old Age Related Information
Use with caution
Breast Feeding Related Information
Contraindicated
Children Related Information
Use with caution
Indications for Propranolol
1. Hypertension
2. Arrhythmias
3. Anxiety
4. Angina
5. Migraine
6. Prophylaxis of myocardial infarction
7. Tremors
8. Phaeochromocytoma
9. Hypertrophic sub aortic stenosis


Interactions for Propranolol
Quinidine: Orthostatic hypotension.
Rifampicin, Phenobarbital, NSAIDs, Thyroid hormones, Smoking: Decrease antihypertensive action of propranolol.
Corticosteroids: Antagonism of hypotensive effect.
Sympathomimetics: Marked hypertension and bradycardia.
Insulin: Hypoglycemic effects prolonged by propranalol and masking of symptoms of hypoglycemia in diabetes.
Lidocaine: Increased levels of lidocaine may occur resulting in toxicity.
Calcium channel blockers: Severe bradycardia especially in those with impaired LV function.
Phenothiazines: Chlorpromazine increases plasma levels of propranolol.
Reserpine: Additive effect resulting in vertigo, syncope or postural hypotension.
Clonidine: May increase the postural hypotension. Severity of rebound hypertension caused by abrupt withdrawal of clonidine enhanced.
Haloperidol: Severe hypotension.
Prazosin: May increase first dose response (acute postural hypotension) of prazosin.
Theophylline: Propranolol antagonises effect of theophylline.
Alcohol: Enhanced hypotensive effect.
ACE inhibitors: Enhanced hypotensive effect.
Lab tests: May interfere with Glaucoma screening test due to reduction in intraocular pressure.
Typical Dosage for Propranolol
40 to 240mg/day
Hypertension: Starts with 80mg once daily or in 2 divided doses and gradually increases up to 320mg/day based on patient`s response in divided doses 12th hourly or 8th hourly.
Maximum daily dose: 640mg.
Sustained release formulations: 120 to 160mg/day. Once daily.
Children: 1mg/kg/day gradually increases to 4mg/kg/day based on patient`s response in 4 divided doses
Maximum dose: 5mg/kg/day.
Arrhythmias & Anxiety: 30mg to 150mg/day in 3 to 5 divided doses.
Children: 0.5 to 4mg/kg/day in 3 to 4 divided doses.
Angina: 40 to 80mg two times daily to 4 times daily.
Migraine: 80 to 120mg/day in divided doses in 12th hourly to 8th hourly. And gradually increases at 1 week intervals to 160mg/day.
Children: 1mg/kg/day four times daily and gradually increases up to 5mg/kg/day based on patient`s response.
Prophylaxis of myocardial infarction: Initiate the therapy with 20mg dose 5days after myocardial infarction. Then give doses of 40mg thrice daily and gradually increases at weekly intervals up to 80mg based on patients response.



Schedule of Propranolol
H
Storage Requirements for Propranolol
Store at controlled room temperature between 20 to 25 degree celcious in a well closed container.
Effects of Missed Dosage of Propranolol
Take the missed dose as soon as noticed and if it is the time for next dose then skip the missed dose. Continue the regular schedule. Do not double the dose.
Effects of Overdose of Propranolol
Treatment is supportive and symptomatic. After ingestion empty the stomach by induced emesis or gastric lavage. Administer activated charcoal. Treat Bradycardia with atropine 0.5 to 1mg.If required administer isoproterinol with caution. Treat hypotension with glucagons and vasopressors like epinephrine. Treat cardiac failure with diuretics and cardiac glycosides. Treat bronchospasm with isoproterinol and aminophylline.

Home Delivery for Propranolol in Your City

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However, we do publish a comprehensive directory of Pharmacies, Chemists and Druggists in cities all over India. You can use this directory to find the medicine stores in your city (or area) that provide home delivery services for propranolol and other medicines and health products. Home delivery services for propranolol may be free or they may cost you depending on the pharmacy and the minimum order requirements. It would be best to get this clarified while placing the order.

Please be aware that you should take propranolol only if a doctor has recommended or prescribed it. Some or all pharmacies who provide a home delivery service for medicines might insist on a prescription for propranolol before they complete the sale. You can get this information while placing the order for propranolol with the pharmacy.

Propranolol is a generic medicine name and there are several brands available for it. Some of the brands for propranolol might be better known than propranolol itself. If the pharmacy that's willing to deliver medicines to your home doesn't have propranolol in stock, you can ask for one of the branded alternatives for propranolol.