propranolol hydrochloride(redirected from Betachron E-R)
Pharmacologic class: Beta-adrenergic blocker (nonselective)
Therapeutic class: Antianginal, anti-arrhythmic (class II), antihypertensive, vascular headache suppressant
Pregnancy risk category C
FDA Box Warning
• In patients with angina pectoris, exacerbations of angina and, in some cases, myocardial infarction (MI) have followed abrupt drug withdrawal. For planned withdrawal, reduce dosage gradually over at least a few weeks and caution patient not to interrupt or stop therapy without physician's advice. If therapy is interrupted and angina exacerbation occurs, consider reinstituting drug and taking other measures to manage unstable angina. As coronary artery disease may be unrecognized, it may be prudent to follow same advice in patients at risk for occult atherosclerotic heart disease who receive drug for other indications.
Blocks stimulation of beta1-adrenergic (myocardial) and beta2-adrenergic (pulmonary, vascular, and uterine) receptor sites. This action decreases cardiac output, slows heart rate, and reduces blood pressure.
Capsules (extended-release, sustained-release): 60 mg, 80 mg, 120 mg, 160 mg
Injection: 1 mg/ml
Oral solution: 4 mg/ml, 8 mg/ml, 80 mg/ml
Tablets: 10 mg, 20 mg, 40 mg, 60 mg, 90 mg
Indications and dosages
➣ Angina pectoris
Adults: 80 to 320 mg P.O. daily in three to four divided doses or 160 mg (extended- or sustained-release) P.O. daily; maximum daily dosage is 320 mg.
Adults: 40 mg P.O. b.i.d. or 80 mg (extended- or sustained-release) P.O. daily. Maximum daily dosage is 640 mg; usual maintenance dosage is 120 to 240 mg/day.
➣ Prophylaxis after MI
Adults: 180 to 240 mg P.O. daily in three to four divided doses; maximum daily dosage is 240 mg.
➣ Hypertrophie subaortic stenosis
Adults: 20 to 40 mg P.O. three to four times daily (before meals and at bedtime) or 80 to 160 mg (extended- or sustained-release) P.O. daily
➣ Adjunctive therapy in pheochromocytoma
Adults: 60 mg P.O. daily in divided doses for 3 days, given after primary therapy with alpha-adrenergic blocker
➣ To prevent migraine or vascular headache
Adults: 80 mg P.O. (extended- or sustained-release) daily; may increase as needed up to 240 mg/day. Effective range is 160 to 240 mg/day.
➣ Essential tremor
Adults: 40 mg P.O. b.i.d.; if necessary, 240 to 320 mg/day. Maximum daily dosage is 320 mg.
Adults: 10 to 30 mg P.O. (tablets or oral solution) three or four times daily
➣ Life-threatening arrhythmias; arrhythmias occurring during anesthesia
Adults: 1 to 3 mg slow I.V. injection. If necessary, give second dose after 2 minutes and additional doses at intervals of no less than 4 hours until desired response occurs.
• Hypersensitivity to drug, its components, or other beta-adrenergic blockers
• Uncompensated heart failure
• Cardiogenic shock
• Sinus bradycardia, heart block greater than first degree
• Bronchospastic disease
Use cautiously in:
• renal or hepatic impairment, sinus node dysfunction, pulmonary disease, diabetes mellitus, hyperthyroidism, Raynaud's syndrome, hypertensive emergencies, myasthenia gravis
• concurrent thioridazine use
• history of severe allergic reactions
• elderly patients
• pregnant or breastfeeding patients
• children (safety not established).
☞ Take apical pulse for 1 full minute. Withhold dose and notify prescriber if patient has bradycardia or tachycardia.
☞ Be aware that I.V. use is usually reserved for arrhythmias that are life-threatening or occur during anesthesia.
• Inject I.V. dose directly into large vein or into tubing of compatible I.V. solution (dextrose 5% in water, normal or half-normal saline solution, or lactated Ringer's solution).
• Don't give as continuous I.V. infusion.
• For intermittent I.V. infusion, dilute with normal saline solution and infuse in 0.1- to 0.2-mg increments over 10 to 15 minutes.
☞ Keep I.V. isoproterenol, atropine, or glucagon at hand in case of emergency.
☞ Don't stop giving drug suddenly. Dosage must be tapered.
CNS: fatigue, asthenia, anxiety, dizziness, drowsiness, insomnia, memory loss, depression, mental status changes, nervousness, paresthesia, nightmares
CV: peripheral vasoconstriction, orthostatic hypotension, bradycardia, arrhythmias, heart failure, myocardial infarction and sudden death (with abrupt withdrawal in angina therapy)
EENT: blurred vision, dry eyes, nasal congestion, rhinitis, sore throat
GI: nausea, vomiting, diarrhea, constipation, dry mouth
GU: erectile dysfunction, decreased libido
Hematologic: purpura, thrombocytopenic purpura
Metabolic: fluid retention, hyperglycemia, hypoglycemia (increased in children), thyrotoxicosis (with abrupt withdrawal in hypertension therapy)
Musculoskeletal: joint pain, back pain, myalgia, muscle cramps
Respiratory: wheezing, bronchospasm, pulmonary edema
Skin: pruritus, rash
Drug-drug. Antacids (aluminum-based): decreased propranolol absorption
Anticholinergics, tricyclic antidepressants: antagonism of cardiac beta-adrenergic blocking effect
Chlorpromazine: additive hypotension
Cimetidine: increased propranolol blood level and risk of toxicity
Digoxin: additive bradycardia
Diuretics, other antihypertensives: increased hypotensive effect
Glucagon, isoproterenol: antagonism of propranolol's effects
Insulin, oral hypoglycemics: impaired glucose tolerance, increased risk of hypoglycemia
Neuromuscular blockers: increased neuromuscular blockade (with high propranolol doses)
Nonsteroidal anti-inflammatory drugs: decreased hypotensive effect
Theophylline: decreased theophylline clearance, antagonism of theophylline's bronchodilating effect
Thioridazine: increased thioridazine blood level, leading to prolonged QT interval
Drug-diagnostic tests. Alkaline phosphatase, blood urea nitrogen, eosinophils, lactate dehydrogenase, serum transaminases, triiodothyronine: increased levels
Glucose: decreased or increased level
Platelets, thyroxine: decreased levels
Drug-behaviors. Acute alcohol ingestion: additive hypotension
• Monitor vital signs, ECG, and central venous pressure.
• Assess fluid balance. Check for signs and symptoms of heart failure.
• Monitor CBC and liver and thyroid function tests.
• Watch closely for signs and symptoms of hypoglycemia, which drug may mask.
• Monitor blood glucose level in diabetic patient, to identify need for altered insulin or oral hypoglycemic dosage. Be aware that in labile diabetes, hypoglycemia may be accompanied by steep blood pressure rise.
• Advise patient to take with meals at same time every day to minimize GI upset.
☞ Caution patient not to stop taking drug suddenly. Tell him dosage must be tapered.
• Tell patient to monitor pulse and to promptly report bradycardia or tachycardia.
• Inform patient that drug may cause muscle aches or bone pain. Advise him to discuss activity recommendations and pain management with prescriber.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration, vision, and alertness.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and behaviors mentioned above.