Inderal ® LA (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: C 16 H 21 NO 2 · HCl Propranolol hydrochloride USP is a stable, white, crystalline solid which is readily soluble in water and ethanol. Its molecular weight is 295.80. Inderal LA is formulated to provide a sustained release of propranolol hydrochloride USP. Inderal LA is available as 60 mg, 80 mg, 120 mg, and 160 mg capsules for oral administration. • Each Inderal LA 60 mg capsule contains 60 mg propranolol hydrochloride USP (equivalent to 52.60 mg of propranolol). • Each Inderal LA 80 mg capsule contains 80 mg propranolol hydrochloride USP (equivalent to 70.14 mg of propranolol). • Each Inderal LA 120 mg capsule contains 120 mg propranolol hydrochloride USP (equivalent to 105.21 mg of propranolol). • Each Inderal LA 160 mg capsule contains 160 mg propranolol hydrochloride USP (equivalent to 140.28 mg of propranolol). The inactive ingredients contained in Inderal LA capsules are: diethyl phthalate, hypromellose phthalate, ethylcellulose, povidone, polyethylene glycol, corn starch, sucrose, hypromellose, gelatin capsules and titanium dioxide. In addition Inderal LA 60 mg capsules contain D&C Red No. 28 and FD&C Blue No. 1; Inderal LA 80 mg and 120 mg capsules contain FD&C Red No. 3 and FD&C Blue No. 1; Inderal LA 160 mg capsules contain FD&C Blue No. 1. FDA approved dissolution specifications differ from USP. inderal-la-01

Hypertension Inderal LA is indicated in the management of hypertension. It may be used alone or used in combination with other antihypertensive agents, particularly a thiazide diuretic. Inderal LA is not indicated in the management of hypertensive emergencies. Angina Pectoris Due to Coronary Atherosclerosis Inderal LA is indicated to decrease angina frequency and increase exercise tolerance in patients with angina pectoris. Migraine Inderal LA 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. Hypertrophic Subaortic Stenosis Inderal LA improves NYHA functional class in symptomatic patients with hypertrophic subaortic stenosis.

General Inderal LA provides propranolol hydrochloride in a sustained-release capsule for administration once daily. If patients are switched from Inderal Tablets to Inderal LA Capsules, care should be taken to assure that the desired therapeutic effect is maintained. Inderal LA should not be considered a simple mg-for-mg substitute for Inderal. Inderal LA has different kinetics and produces lower blood levels. Retitration may be necessary, especially to maintain effectiveness at the end of the 24-hour dosing interval. Hypertension The usual initial dosage is 80 mg Inderal LA once daily, whether used alone or added to a diuretic. The dosage may be increased to 120 mg once daily or higher until adequate blood pressure control is achieved. The usual maintenance dosage is 120 to 160 mg once daily. In some instances a dosage of 640 mg may be required. The time needed for full hypertensive response to a given dosage is variable and may range from a few days to several weeks. Angina Pectoris Starting with 80 mg Inderal LA once daily, dosage should be gradually increased at three- to seven-day intervals until optimal response is obtained. Although individual patients may respond at any dosage level, the average optimal dosage appears to be 160 mg once daily. In angina pectoris, the value and safety of dosage exceeding 320 mg per day have not been established. If treatment is to be discontinued, reduce dosage gradually over a period of a few weeks . Migraine The initial oral dose is 80 mg Inderal LA once daily. The usual effective dose range is 160 to 240 mg once daily. The dosage may be increased gradually to achieve optimal migraine prophylaxis. If a satisfactory response is not obtained within four to six weeks after reaching the maximal dose, Inderal LA therapy should be discontinued. It may be advisable to withdraw the drug gradually over a period of several weeks depending on the patient's age, comorbidity, and dose of Inderal LA. Hypertrophic Subaortic Stenosis The usual dosage is 80 to 160 mg Inderal LA once daily.

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 unstable 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 . Cutaneous reactions, including Stevens-Johnson Syndrome, toxic epidermal necrolysis, exfoliative dermatitis, erythema multiforme, and urticaria, have been reported with use of propranolol . 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 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. Hypoglycemia Beta-blockers may prevent early warning signs of hypoglycemia, such as tachycardia, and increase the risk for severe or prolonged hypoglycemia at any time during treatment, especially in patients with diabetes mellitus or children and patients who are fasting (i.e., surgery, not eating regularly, or are vomiting). If severe hypoglycemia occurs, patients should be instructed to seek emergency treatment. 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 T 4 and reverse T 3 , and decreasing T 3 . Wolff-Parkinson-White Syndrome Beta-adrenergic blockade in patients with Wolff-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.

Drug Interactions Caution should be exercised when Inderal LA is administered with drugs that have an affect on CYP2D6, 1A2, or 2C19 metabolic pathways. Co-administration of such drugs with propranolol may lead to clinically relevant drug interactions and changes on its efficacy and/or toxicity . Alcohol when used concomitantly with propranolol, may increase plasma levels of propranolol. Cardiovascular Drugs Antiarrhythmics Propafenone has negative inotropic and beta-blocking properties that can be additive to those of propranolol. Quinidine increases the concentration of propranolol and produces greater degrees of clinical beta-blockade and may cause postural hypotension. Amiodarone is an antiarrhythmic agent with negative chronotropic properties that may be additive to those seen with β-blockers such as propranolol. The clearance of lidocaine is reduced with administration of propranolol. Lidocaine toxicity has been reported following co-administration with propranolol. Caution should be exercised when administering Inderal LA with drugs that slow A-V nodal conduction, e.g., lidocaine and calcium channel blockers. Digitalis Glycosides Both digitalis glycosides and beta-blockers slow atrioventricular conduction and decrease heart rate. Concomitant use can increase the risk of bradycardia. Calcium Channel Blockers Caution should be exercised when patients receiving a beta-blocker are administered a calcium-channel-blocking drug with negative inotropic and/or chronotropic effects. Both agents may depress myocardial contractility or atrioventricular conduction. There have been reports of significant bradycardia, heart failure, and cardiovascular collapse with concurrent use of verapamil and beta-blockers. Co-administration of propranolol and diltiazem in patients with cardiac disease has been associated with bradycardia, hypotension, high degree heart block, and heart failure. ACE Inhibitors When combined with beta-blockers, ACE inhibitors can cause hypotension, particularly in the setting of acute myocardial infarction. The antihypertensive effects of clonidine may be antagonized by beta-blockers. Inderal LA should be administered cautiously to patients withdrawing from clonidine. Alpha Blockers Prazosin has been associated with prolongation of first dose hypotension in the presence of beta-blockers. Postural hypotension has been reported in patients taking both beta-blockers and terazosin or doxazosin. Reserpine Patients receiving catecholamine-depleting drugs, such as reserpine should be closely observed for excessive reduction of resting sympathetic nervous activity, which may result in hypotension, marked bradycardia, vertigo, syncopal attacks, or orthostatic hypotension. Inotropic Agents Patients on long-term therapy with propranolol may experience uncontrolled hypertension if administered epinephrine as a consequence of unopposed alpha-receptor stimulation. Epinephrine is therefore not indicated in the treatment of propranolol overdose . Isoproterenol and Dobutamine Propranolol is a competitive inhibitor of beta-receptor agonists, and its effects can be reversed by administration of such agents, e.g., dobutamine or isoproterenol. Also, propranolol may reduce sensitivity to dobutamine stress echocardiography in patients undergoing evaluation for myocardial ischemia. Non-Cardiovascular Drugs Nonsteroidal Anti-Inflammatory Drugs Nonsteroidal anti-inflammatory drugs (NSAIDs) have been reported to blunt the antihypertensive effect of beta-adrenoreceptor blocking agents. Administration of indomethacin with propranolol may reduce the efficacy of propranolol in reducing blood pressure and heart rate. Antidepressants The hypotensive effects of MAO inhibitors or tricyclic antidepressants may be exacerbated when administered with beta-blockers by interfering with the beta-blocking activity of propranolol. Anesthetic Agents Methoxyflurane and trichloroethylene may depress myocardial contractility when administered with propranolol. Warfarin Propranolol when administered with warfarin increases the concentration of warfarin. Prothrombin time, therefore, should be monitored. Neuroleptic Drugs Hypotension and cardiac arrest have been reported with the concomitant use of propranolol and haloperidol. Thyroxine Thyroxine may result in a lower than expected T 3 concentration when used concomitantly with propranolol.