Propranolol Hydrochloride
Common Brand Names: Inderal
Therapeutic Class: Nonselective beta-adrenergic blocking antiarrhythmic agent
Common Injectable Dosage Forms:
Injection: 1 mg/mL in vials and ampoules
Dosage Ranges:
For arrhythmias which are life-threatening or occur during anesthesia, the usual adult IV dosage is 0.5-3 mg. If necessary, a second dose may be administered after 2 minutes, with additional doses no less than 4 hours apart until desired response is obtained.
Although parenteral use is not recommended in pediatric patients, doses of 10-20 mcg/kg infused over 10 minutes have been used.
Therapeutic Drug Level: Between 50-200 nanograms/mL
Administration and Stability: The drug may be administered undiluted (1 mg/mL) by direct IV injection at a rate not exceeding 1 mg/minute. Careful monitoring of ECG and central venous pressure should be performed during IV propranolol therapy. Stable for 24 hours at room temperature when g/mL) by direct IV injection at a rate not exceeding 1 mg/minute. Careful monitoring of ECG and central venous pressure should be performed during IV propranolol therapy. Stable for 24 hours at room temperature when diluted in D5W, NS, and other solutions. pH 2.8-4
Pharmacology/Pharmacokinetics: Propranolol inhibits response to adrenergic stimuli by competitively blocking beta-adrenergic receptors in the myocardium and within bronchial and vascular smooth muscle. The results in, among other actions, a decrease in heart rate, myocardial contractility, cardiac output, and conduction velocity through the SA and AV nodes. Following IV administration, the effects are almost immediate. The drug is widely distributed to body fluids and tissues, is highly protein bound, and extensively metabolized in the liver with excretion via the urine and feces.
Drug and Lab Interactions: Concomitant use with phenothiazines may cause additive hypotension. Propranolol will antagonize the stimulatory effects of SYMPATHOMIMETIC agents. Antimuscarinic agents and drugs with anticholinergic effects will antagonize the bradycardic action of propranolol. Additive bradycardia when used with cardiac glycosides may be dangerous to the patient. CIMETIDINE may reduce the clearance of propranolol by inhibiting hepatic metabolism. Propranolol decreases the clearance of theophylline in a dose-dependent manner.
Contraindications/Precautions: Contraindicated in patients with Raynaud’s syndrome, malignant hypertension, bronchial asthma, myasthenia gravis, sinus bradycardia and heart block greater than first degree, and congestive heart failure. The drug should generally not be used in any patient with bronchospastic disease. It should be used with caution in patients with hyperthyroidism or sinus node dysfunction. Pregnancy Category C.
Monitoring Parameters: ECG, blood pressure, heart rate
Adverse Effects: Hypotension is the most common side effect with IV infusion. Other reported effects are bradycardia, PVCs, dizziness, weakness, nausea, and headache. Several CNS effects have been reported with propranolol withdrawal, an in patients with severe heart disease, elevated BUN levels have occurred.
Common Clinical Applications: Primary IV use is in patients with life-threatening arrhythmias, but other uses include management of hypertension, reduction of mortality in myocardial infarction, pheochromocytoma, and angina pectoris.
