PROPRANOLOL HYDROCHLORIDE

Propranolol Hydrochloride, USP is a synthetic beta-adrenergic receptor blocking agent chemically described as (+)-1-(isopropylamino)-3-(1-naphthyloxy)-2-propanol hydrochloride. Its structural formula is: 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. Propranolol Hydrochloride Injection, USP is available as a sterile injectable solution for intravenous administration. Each mL contains 1 mg of Propranolol Hydrochloride, USP in Water for Injection, USP. The pH is adjusted with anhydrous Citric Acid, USP. Structural Formula

Cardiac Arrhythmias Intravenous administration is usually reserved for life-threatening arrhythmias or those occurring under anesthesia. 1. Supraventricular arrhythmias Intravenous propranolol is indicated for the short-term treatment of supraventricular tachycardia, including Wolff‑Parkinson‑White syndrome and thyrotoxicosis, to decrease ventricular rate. Use in patients with atrial flutter or atrial fibrillation should be reserved for arrythmias unresponsive to standard therapy or when more prolonged control is required. Reversion to normal sinus rhythm has occasionally been observed, predominantly in patients with sinus or atrial tachycardia. 2. Ventricular tachycardias With the exception of those induced by catecholamines or digitalis, propranolol is not the drug of first choice. In critical situations when cardioversion techniques or other drugs are not indicated or are not effective, propranolol may be considered. If, after consideration of the risks involved, propranolol is used, it should be given intravenously in low dosage and very slowly, as the failing heart requires some sympathetic drive for maintenance of myocardial tone (see DOSAGE AND ADMINISTRATION ). Some patients may respond with complete reversion to normal sinus rhythm, but reduction in ventricular rate is more likely. Ventricular arrhythmias do not respond to propranolol as predictably as do the supraventricular arrhythmias. Intravenous propranolol is indicated for the treatment of persistent premature ventricular extrasystoles that impair the well‑being of the patient and do not respond to conventional measures. 3. Tachyarrhythmias of digitalis intoxication Intravenous propranolol is indicated to control ventricular rate in life-threatening digitalis-induced arrhythmias. Severe bradycardia may occur (see OVERDOSAGE ). 4. Resistant tachyarrhythmias due to excessive catecholamine action during anesthesia Intravenous propranolol is indicated to abolish tachyarrhythmias due to excessive catecholamine action during anesthesia when other measures fail. These arrhythmias may arise because of release of endogenous catecholamines or administration of catecholamines. All general inhalation anesthetics produce some degree of myocardial depression. Therefore, when propranolol is used to treat arrhythmias during anesthesia, it should be used with extreme caution, usually with constant monitoring of the ECG and central venous pressure (see WARNINGS ).

Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. The usual dose is 1 to 3 mg administered under careful monitoring, such as electrocardiography and central venous pressure. The rate of administration should not exceed 1 mg (1 mL) per minute to diminish the possibility of lowering blood pressure and causing cardiac standstill. Sufficient time should be allowed for the drug to reach the site of action even when a slow circulation is present. If necessary, a second dose may be given after two minutes. Thereafter, additional drug should not be given in less than four hours. Additional propranolol hydrochloride should not be given when the desired alteration in rate or rhythm is achieved. Transfer to oral therapy as soon as possible.

Propranolol is contraindicated in 1) cardiogenic shock; 2) sinus bradycardia and greater than first-degree block; 3) bronchial asthma; and 4) in patients with known hypersensitivity to propranolol hydrochloride.

In a series of 225 patients, there were 6 deaths (see CLINICAL STUDIES ). Cardiovascular events (hypotension, congestive heart failure, bradycardia, and heart block) were the most common. The only other event reported by more than one patient was nausea. Other adverse events for intravenous propranolol, reported during post-marketing surveillance include cardiac arrest, dyspnea, and cutaneous ulcers. The following adverse events have been reported with use of formulations of sustained- or immediate-release oral propranolol and may be expected with intravenous propranolol. Cardiovascular Bradycardia; congestive heart failure; intensification of AV block; hypotension; paresthesia of hands; thrombocytopenic purpura; arterial insufficiency, usually of the Raynaud type. Central Nervous System Light-headedness; mental depression manifested by insomnia, lassitude, weakness, fatigue; reversible mental depression progressing to catatonia; visual disturbances; hallucinations; vivid dreams; an acute reversible syndrome characterized by disorientation for time and place, short-term memory loss, emotional lability, slightly clouded sensorium, and decreased performance on neuropsychometrics. For immediate‑release formulations, fatigue, lethargy, and vivid dreams appear dose-related. Gastrointestinal Nausea, vomiting, epigastric distress, abdominal cramping, diarrhea, constipation, mesenteric arterial thrombosis, ischemic colitis. Allergic Pharyngitis and agranulocytosis; erythematous rash, fever combined with aching and sore throat; laryngospasm, and respiratory distress. Respiratory Bronchospasm. Hematologic Agranulocytosis, nonthrombocytopenic purpura, thrombocytopenic purpura. Autoimmune In extremely rare instances, systemic lupus erythematosus has been reported. Miscellaneous Alopecia, LE-like reactions, psoriaform rashes, dry eyes, male impotence, and Peyronie’s disease have been reported rarely. Oculomucocutaneous reactions involving the skin, serous membranes and conjunctivae reported for a beta-blocker (practolol) have not been associated with propranolol. To report SUSPECTED ADVERSE REACTIONS, contact Hikma Pharmaceuticals USA Inc. at 1-877-845-0689 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .

Interactions with Substrates, Inhibitors or Inducers of Cytochrome P-450 Enzymes Because propranolol’s metabolism involves multiple pathways in the cytochrome P-450 system (CYP2D6, 1A2, 2C19), administration of propranolol with drugs that are metabolized by, or affect the activity (induction or inhibition) of one or more of these pathways may lead to clinically relevant drug interactions (see PRECAUTIONS, Drug Interactions ). Substrates or Inhibitors of CYP2D6 Blood levels of propranolol may be increased by administration of propranolol with substrates or inhibitors of CYP2D6, such as amiodarone, cimetidine, delavirdine, fluoxetine, paroxetine, quinidine, and ritonavir. No interactions were observed with either ranitidine or lansoprazole. Substrates or Inhibitors of CYP1A2 Blood levels of propranolol may be increased by administration of propranolol with substrates or inhibitors of CYP1A2, such as imipramine, cimetidine, ciprofloxacin, fluvoxamine, isoniazid, ritonavir, theophylline, zileuton, zolmitriptan, and rizatriptan. Substrates or Inhibitors of CYP2C19 Blood levels of propranolol may be increased by administration of propranolol with substrates or inhibitors of CYP2C19, such as fluconazole, cimetidine, fluoxetine, fluvoxamine, teniposide, and tolbutamide. No interaction was observed with omeprazole. Inducers of Hepatic Drug Metabolism Blood levels of propranolol may be decreased by administration of propranolol with inducers such as rifampin and ethanol. Cigarette smoking also induces hepatic metabolism and has been shown to increase up to 100% the clearance of propranolol, resulting in decreased plasma concentrations. Cardiovascular Drugs Antiarrhythmics The AUC of propafenone is increased by more than 200% with co-administration of propranolol. The metabolism of propranolol is reduced by co-administration of quinidine, leading to a 2- to 3-fold increased blood concentrations and greater beta-blockade. The metabolism of lidocaine is inhibited by co-administration of propranolol, resulting in a 25% increase in lidocaine concentrations. Calcium Channel Blockers The mean C max and AUC of propranolol are increased respectively, by 50% and 30% by co-administration of nisoldipine and by 80% and 47%, by co-administration of nicardipine. The mean values of C max and AUC of nifedipine are increased by 64% and 79%, respectively, by co-administration of propranolol. Propranolol does not affect the pharmacokinetics of verapamil and norverapamil. Verapamil does not affect the pharmacokinetics of propranolol. Non-Cardiovascular Drugs Migraine Drugs Administration of zolmitriptan or rizatriptan with propranolol resulted in increased concentrations of zolmitriptan (AUC increased by 56% and C max by 37%) or rizatriptan (the AUC and C max were increased by 67% and 75%, respectively). Theophylline Co-administration of theophylline with propranolol decreases theophylline clearance by 33% to 52%. Benzodiazepines Propranolol can inhibit the metabolism of diazepam, resulting in increased concentrations of diazepam and its metabolites. Diazepam does not alter the pharmacokinetics of propranolol. The pharmacokinetics of oxazepam, triazolam, lorazepam, and alprazolam are not affected by co-administration of propranolol. Neuroleptic Drugs Co-administration of propranolol at doses greater than or equal to 160 mg/day resulted in increased thioridazine plasma concentrations ranging from 50% to 370% and increased thioridazine metabolites concentrations ranging from 33% to 210%. Co-administration of chlorpromazine with propranolol resulted in increased plasma levels of both drugs (70% increase in propranolol concentrations). Anti-Ulcer Drugs Co-administration of propranolol with cimetidine, a non-specific CYP450 inhibitor, increased propranolol concentrations by about 40%. Co‑administration with aluminum hydroxide gel (1200 mg) resulted in a 50% decrease in propranolol concentrations. Co-administration of metoclopramide with propranolol did not have a significant effect on propranolol’s pharmacokinetics. Lipid Lowering Drugs Co-administration of cholesteramine or colestipol with propranolol resulted in up to 50% decrease in propranolol concentrations. Co-administration of propranolol with lovastatin or pravastatin decreased 20% to 25% the AUC of both, but did not alter their pharmacodynamics. Propranolol did not have an effect on the pharmacokinetics of fluvastatin. Warfarin Concomitant administration of propranolol and warfarin has been shown to increase warfarin bioavailability and increase prothrombin time. Interactions with Substrates, Inhibitors or Inducers of Cytochrome P-450 Enzymes Because propranolol’s metabolism involves multiple pathways in the cytochrome P-450 system (CYP2D6, 1A2, 2C19), administration of propranolol with drugs that are metabolized by, or affect the activity (induction or inhibition) of one or more of these pathways may lead to clinically relevant drug interactions (see PRECAUTIONS, Drug Interactions ). Drug Interactions Caution should be exercised when propranolol is administered with drugs that have an effect on CYP2D6, 1A2, or 2C19 metabolic pathways. Co-administration of such drugs with propranolol may lead to clinically relevant drug interactions and changes in its efficacy and/or toxicity (see CLINICAL PHARMACOLOGY, Drug Interactions ). 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 a greater degree of clinical beta-blockade and may cause postural hypotension. Disopyramide is a Type I antiarrhythmic drug with potent negative inotropic and chronotropic effects and has been associated with severe bradycardia, asystole and heart failure when administered with propranolol. Amiodarone is an antiarrhythmic agent with negative chronotropic properties that may be additive to those seen with propranolol. The clearance of lidocaine is reduced when administered with propranolol. Lidocaine toxicity has been reported following co-administration with propranolol. Caution should be exercised when administering propranolol with drugs that slow A-V nodal conduction, e.g., digitalis, lidocaine and calcium channel blockers. 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. ACE inhibitors have been reported to increase bronchial hyperreactivity when administered with propranolol. The antihypertensive effects of clonidine may be antagonized by beta-blockers. Propranolol 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, with propranolol should be closely observed for excess reduction of resting sympathetic nervous activity, which may result in hypotension, marked bradycardia, vertigo, syncopal attacks, or orthostatic hypotension. Administration of reserpine with propranolol may also potentiate depression. 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 (see OVERDOSAGE ). 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 Non-Steroidal Anti-Inflammatory Drugs Non-steroidal 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 Administration of propranolol with warfarin increases the concentration of warfarin. Therefore, the prothrombin time 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.