Propranolol hydrochloride

Chemical Properties

Off-White to Light-Yellow Cyrstalline Solid

Uses

Propranolol, a β-adrenergic blocker, is most commonly used to reduce blood pressure; treatment of over-active thyroid and some types of tremor; prevention of migraine headaches and some heart-rhythm problems; used to decrease the number of angina attacks (pain from an inadequate oxygen supply to the heart); used after a heart attack to prevent further damage to the heart.

Uses

For the prophylaxis of migraine

Uses

β?Adrenergic blocker. Antihypertensive; antianginal; antiarrhythmic (class II).

Uses

(±)-Propranolol hydrochloride has been used:

• to determine whether autonomic nervous system mediated the promotive effect on skin microcirculation in rat
• as a non-selective β- receptor blocker to reduce the arrhythmogenic events
• to study its effect on oxygen-induced retinopathy in mice

brand name

Inderal (Wyeth); Innopran (Reliant).

General Description

Propranolol hydrochloride is easily soluble in ethanol and water.

Biochem/physiol Actions

Propranolol hydrochloride is a β-adrenoceptor antagonist. Its action at β2 receptor results in bronchoconstriction. Due to its lipophilic nature, propranolol can penetrate to the central nervous system and has a negative effect. It serves as a 5-HT1/5-HT2 serotonin receptor antagonist. Propranolol hydrochloride is useful as an antihypertensive drug, cardiac depressant and also in the treatment of angina pectoris. It decreases the effect of stress and exercise on heart by reducing the rate of contraction and conduction of impulse. It is known to competitively block the action of catecholamines.

Clinical Use

Beta-adrenoceptor blocker:
Hypertension
Phaeochromocytoma
Angina
Arrhythmias
Anxiety
Migraine prophylaxis

Veterinary Drugs and Treatments

While propranolol is used for hypertension, migraine headache prophylaxis, and angina in human patients, it is used primarily in veterinary medicine for its antiarrhythmic effects. Dysrhythmias treated with propranolol include: atrial premature complexes, ventricular premature complexes, supraventricular premature complexes and tachyarrhythmias, ventricular or atrial tachyarrhythmias secondary to digitalis, atrial tachycardia secondary to Wolff-Parkinson-White (WPW) with normal QRS complexes, and atrial fibrillation (generally in combination with digoxin). Propranolol reportedly improves cardiac performance in animals with hypertrophic cardiomyopathy. It has been used to treat systemic hypertension and clinical signs associated with thyrotoxicosis and pheochromocytoma.

Drug interactions

Potentially hazardous interactions with other drugs
Anaesthetics: enhanced hypotensive effect; risk of bupivacaine toxicity increased.
Analgesics: NSAIDs antagonise hypotensive effect.
Anti-arrhythmics: increased risk of myocardial depression and bradycardia; increased risk of bradycardia, myocardial depression and AV block with amiodarone; concentration increased by propafenone and possibly dronedarone; increased risk of myocardial depression and bradycardia with flecainide; increased risk of lidocaine toxicity.
Antibacterials: metabolism increased by rifampicin.
Antidepressants: enhanced hypotensive effect with MAOIs; concentration increased by fluvoxamine; concentration of imipramine increased.
Antihypertensives; enhanced hypotensive effect; increased risk of withdrawal hypertension with clonidine; increased risk of first dose hypotensive effect with post-synaptic alpha-blockers such as prazosin.
Antimalarials: increased risk of bradycardia with mefloquine.
Antipsychotics enhanced hypotensive effect with phenothiazines; concentration of both drugs increased with chlorpromazine.
Calcium-channel blockers: increased risk of bradycardia and AV block with diltiazem; hypotension and heart failure possible with nifedipine and nisoldipine; asystole, severe hypotension and heart failure with verapamil.
Cytotoxics: possible increased risk of bradycardia with crizotinib.
Diuretics: enhanced hypotensive effect.
Fingolimod: possibly increased risk of bradycardia.
Moxisylyte: possible severe postural hypotension.
Sympathomimetics: severe hypertension with adrenaline and noradrenaline and possibly with dobutamine.

Metabolism

Propranolol is subject to considerable hepatic-tissue binding and first-pass metabolism. It is metabolised in the liver to an active metabolite (4-hydroxypropranolol) and several inactive ones.
The metabolites and small amounts of unchanged drug are excreted in the urine.

storage

Store at RT