What is the typical dosage and usage of Propranolol (beta-blocker) for treating hypertension, angina, and arrhythmias?

Propranolol Dosage and Usage for Hypertension, Angina, and Arrhythmias

For hypertension, propranolol is typically started at 80 mg once daily (extended-release) or 40-160 mg in divided doses, with maintenance dosing of 120-160 mg daily; for angina, 80 mg once daily initially, titrated to 160 mg daily; and for arrhythmias, 0.5-1 mg IV over 1 minute up to a total dose of 0.1 mg/kg. 1, 2

Hypertension Management

• Initial dosage for hypertension is 80 mg once daily using extended-release capsules, either alone or combined with a diuretic 1
• Dosage may be increased to 120 mg once daily or higher until adequate blood pressure control is achieved 1
• Usual maintenance dosage ranges from 120 to 160 mg once daily, though some patients may require up to 640 mg daily 1
• Full hypertensive response may take several days to weeks to develop 1
• Propranolol is typically used as a second-step drug when diuretic therapy alone is not effective, with combination therapy being effective in over 80% of patients with mild to moderate hypertension 3

Angina Pectoris Treatment

• Starting dose is 80 mg once daily using extended-release capsules 1
• Dosage should be gradually increased at three to seven-day intervals until optimal response is obtained 1
• Average optimal dosage appears to be 160 mg once daily, though individual patients may respond at any dosage level 1
• Maximum recommended dosage for angina is 320 mg per day, as safety and efficacy beyond this dose have not been established 1
• In severe angina pectoris (NYHA class III or IV), higher doses of 500-800 mg daily may be required for optimal treatment 4
• Long-term propranolol therapy for angina has shown an average yearly mortality rate of 3.8% with a cumulative 5-year mortality rate of 19% 5

Arrhythmia Management

• For acute management of arrhythmias, propranolol is administered intravenously at 0.5-1 mg over 1 minute 2
• Can repeat 1 mg IV at 2-minute intervals, up to 3 doses total 2
• For oral maintenance therapy in supraventricular tachycardias, propranolol is dosed at 30-60 mg in divided doses or as a single dose with long-acting formulations 2
• Maintenance dose ranges from 40-160 mg in divided doses or as a single dose with long-acting formulations 2

Pharmacokinetics and Formulations

• Long-acting propranolol (extended-release) has a prolonged terminal half-life of 8-11 hours due to slower absorption from the gut 6
• Systemic bioavailability of extended-release propranolol is 30-50% less than conventional formulations due to increased hepatic metabolism 6
• Extended-release formulations provide relatively constant plasma concentrations and clinically significant beta-blockade throughout a 24-hour dosing interval 6
• When switching from immediate-release tablets to extended-release capsules, retitration may be necessary to maintain effectiveness at the end of the 24-hour dosing interval 1

Precautions and Contraindications

• Avoid in patients with asthma or obstructive airway disease 2
• Avoid in patients with decompensated heart failure 2
• Avoid in patients with AV block greater than first degree or SA node dysfunction (in absence of pacemaker) 2
• Avoid in patients with cardiogenic shock 2
• Avoid in patients with pre-excited atrial fibrillation or flutter 2
• If treatment is to be discontinued, reduce dosage gradually over a period of a few weeks to prevent rebound effects 1
• Common adverse effects include hypotension, bradycardia, bronchospasm, and worsening heart failure 2

Special Considerations

• Patients with a cardiothoracic ratio greater than 0.5 are at higher risk of developing heart failure during propranolol therapy 5
• Patients whose reduction of angina with propranolol is less than 50% have a nearly four-fold greater mortality rate than those with 50% or more reduction 5
• Propranolol may increase the risk of cardiogenic shock in acute myocardial infarction 5
• For patients with refractory rate control, other beta-blockers like bisoprolol (2.5-5 mg once daily, maximum 10 mg) may be considered 7
• When monitoring efficacy for rate control, target resting heart rate <80 bpm for symptomatic management or <110 bpm for asymptomatic patients with preserved left ventricular function 7