
Angina Pectoris
There have been reports of exacerbation of angina and, in some cases, myocardial infarction, following abrupt discontinuance of propranolol therapy. Therefore, when discontinuance of propranolol is planned, the dosage should be gradually reduced over at least a few weeks and the patient should be cautioned against interruption or cessation of therapy without the physician’s advice. If propranolol therapy is interrupted and exacerbation of angina occurs, it usually is advisable to reinstitute propranolol therapy and take other measures appropriate for the management of angina pectoris. Since coronary artery disease may be unrecognized, it may be prudent to follow the above advice in patients considered at risk of having occult atherosclerotic heart disease who are given propranolol for other indications.
Hypersensitivity and Skin Reactions
Hypersensitivity reactions, including anaphylactic/anaphylactoid reactions, have been associated with the administration of propranolol (see ADVERSE REACTIONS).
Cutaneous reactions, including Stevens-Johnson Syndrome, toxic epidermal necrolysis, exfoliative dermatitis, erythema multiforme, and urticaria, have been reported with use of propranolol (see ADVERSE REACTIONS).
Cardiac Failure
Sympathetic stimulation may be a vital component supporting circulatory function in patients with congestive heart failure, and its inhibition by beta blockade may precipitate more severe failure. Although beta blockers should be avoided in overt congestive heart failure, some have been shown to be highly beneficial when used with close follow-up in patients with a history of failure who are well compensated and are receiving additional therapies, including diuretics as needed. Beta-adrenergic blocking agents do not abolish the inotropic action of digitalis on heart muscle.
In Patients without a History of Heart Failure, continued use of beta blockers can, in some cases, lead to cardiac failure.
Nonallergic Bronchospasm (e.g., Chronic Bronchitis, Emphysema)
In general, patients with bronchospastic lung disease should not receive beta blockers. Propranolol should be administered with caution in this setting since it may provoke a bronchial asthmatic attack by blocking bronchodilation produced by endogenous and exogenous catecholamine stimulation of beta-receptors.
Major Surgery
Chronically administered beta-blocking therapy should not be routinely withdrawn prior to major surgery, however the impaired ability of the heart to respond to reflex adrenergic stimuli may augment the risks of general anesthesia and surgical procedures.
Diabetes and Hypoglycemia
Beta-adrenergic blockade may prevent the appearance of certain premonitory signs and symptoms (pulse rate and pressure changes) of acute hypoglycemia, especially in labile insulin-dependent diabetics. In these patients, it may be more difficult to adjust the dosage of insulin.
Propranolol therapy, particularly when given to infants and children, diabetic or not, has been associated with hypoglycemia especially during fasting as in preparation for surgery. Hypoglycemia has been reported in patients taking propranolol after prolonged physical exertion and in patients with renal insufficiency.
Thyrotoxicosis
Beta-adrenergic blockade may mask certain clinical signs of hyperthyroidism. Therefore, abrupt withdrawal of propranolol may be followed by an exacerbation of symptoms of hyperthyroidism, including thyroid storm. Propranolol may change thyroid-function tests, increasing T4 and reverse T3 and decreasing T3.
Wolff-Parkinson-White Syndrome
Beta-adrenergic blockade in patients with Wolf-Parkinson-White Syndrome and tachycardia has been associated with severe bradycardia requiring treatment with a pacemaker. In one case, this result was reported after an initial dose of 5 mg propranolol.
Pheochromocytoma
Blocking only the peripheral dilator (beta) action of epinephrine with propranolol leaves its constrictor (alpha) action unopposed. In the event of hemorrhage or shock, there is a disadvantage in having both beta and alpha blockade since the combination prevents the increase in heart rate and peripheral vasoconstriction needed to maintain blood pressure.
There is currently no manufacturer warning information available for this drug.
Hypertension
Propranolol hydrochloride tablets are indicated in the management of hypertension. It may be used alone or used in combination with other antihypertensive agents, particularly a thiazide diuretic. Propranolol hydrochloride is not indicated in the management of hypertensive emergencies.
Angina Pectoris Due to Coronary Atherosclerosis
Propranolol hydrochloride tablets are indicated to decrease angina frequency and increase exercise tolerance in patients with angina pectoris.
Atrial Fibrillation
Propranolol hydrochloride tablets are indicated to control ventricular rate in patients with atrial fibrillation and a rapid ventricular response.
Myocardial Infarction
Propranolol is indicated to reduce cardiovascular mortality in patients who have survived the acute phase of myocardial infarction and are clinically stable.
Migraine
Propranolol is indicated for the prophylaxis of common migraine headache. The efficacy of propranolol in the treatment of a migraine attack that has started has not been established, and propranolol is not indicated for such use.
Essential Tremor
Propranolol is indicated in the management of familial or hereditary essential tremor. Familial or essential tremor consists of involuntary, rhythmic, oscillatory movements, usually limited to the upper limbs. It is absent at rest, but occurs when the limb is held in a fixed posture or position against gravity and during active movement. Propranolol causes a reduction in the tremor amplitude, but not in the tremor frequency. Propranolol is not indicated for the treatment of tremor associated with Parkinsonism.
Hypertrophic Subaortic Stenosis
Propranolol improves NYHA functional class in symptomatic patients with hypertrophic subaortic stenosis.
Pheochromocytoma
Propranolol is indicated as an adjunct to alpha-adrenergic blockade to control blood pressure and reduce symptoms of catecholamine-secreting tumors.
Propranolol hydrochloride is a synthetic beta-adrenergic receptor blocking agent chemically described as 2-Propanol, 1-[(1-methylethyl)amino]-3-(1-naphthalenyloxy)-, hydrochloride,(±)-. Its molecular and structural formulae are:
C16H21NO2 • HCl M.W. 295.80
Propranolol hydrochloride is a stable, white crystalline solid which is readily soluble in water and ethanol. Its molecular weight is 295.80.
Propranolol hydrochloride is available as 10 mg, 20 mg, 40 mg and 80 mg tablets for oral administration.
Propranolol Hydrochloride Tablets USP 10 mg, 20 mg, 40 mg, and 80 mg contain the following inactive ingredients: anhydrous lactose, colloidal silicon dioxide, croscarmellose sodium, D&C Yellow No. 10, magnesium stearate, microcrystalline cellulose and stearic acid.
Propranolol Hydrochloride Tablets USP 10 mg and 80 mg also contain FD&C Yellow No. 6.
Propranolol Hydrochloride Tablets USP 20 mg and 40 mg also contain FD&C Blue No. 1.