PROPRANOLOL

Propranolol hydrochloride 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 M.W. 295.80 Propranolol hydrochloride is a stable, white, crystalline solid which is readily soluble in water and ethanol. Propranolol Hydrochloride Injection, USP is available as a 1 mg/mL sterile injectable solution for intravenous administration. Each mL contains 1 mg of propranolol hydrochloride in Water for Injection. The pH is adjusted to 2.8 to 4.0 with citric acid monohydrate. structure

Cardiac Arrhythmias Intravenous administration is usually reserved for life-threatening arrhythmias or those occurring under anesthesia. 1. Supraventricular arrhythmia s 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 ). Cardiac Arrhythmias Intravenous administration is usually reserved for life-threatening arrhythmias or those occurring under anesthesia. 1. Supraventricular arrhythmia s 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 ).

The usual dose is 1 mg to 3 mg administered under careful monitoring, such as electrocardiographiy 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 and/or rhythm is achieved. Transfer to oral therapy as soon as possible. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.

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

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 postmarketing 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 Lightheadedness; 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, psoriasiform 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. 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 Lightheadedness; 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, psoriasiform 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.