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

Propranolol Dosing for Hypertension, Angina, and Arrhythmias

Hypertension

For hypertension, start with propranolol extended-release 80 mg once daily, titrating to a usual maintenance dose of 120-160 mg once daily, with a maximum of 640 mg daily if needed. 1

• The initial dose of 80 mg can be used alone or added to a diuretic therapy 1
• Dosage may be increased to 120 mg once daily or higher until adequate blood pressure control is achieved 1
• The time needed for full hypertensive response to a given dosage is variable and may range from a few days to several weeks 1
• For immediate-release formulation, use 80-160 mg daily divided into 2 doses 2
• In mild to moderately severe hypertension, propranolol in doses up to 480 mg/day in combination with a thiazide diuretic has been found effective in over 80% of patients on long-term therapy 3

Critical pre-treatment assessment: Check for absolute contraindications including second or third-degree heart block, decompensated heart failure, asthma/obstructive airway disease, cardiogenic shock, and sinus node dysfunction without pacemaker 2

Angina Pectoris

For angina, start with propranolol extended-release 80 mg once daily, gradually increasing at 3-7 day intervals to an average optimal dose of 160 mg once daily, with a maximum of 320 mg daily. 1

• The average optimal dosage appears to be 160 mg once daily, though individual patients may respond at any dosage level 1
• In angina pectoris, the value and safety of dosage exceeding 320 mg per day have not been established 1
• For severe angina (NYHA class III or IV), the average optimum dosage is 500-800 mg daily, which may be higher than doses used for hypertension 4
• A dose-dependent anti-anginal effect has been demonstrated, with progressive reduction in angina attacks as dosage increases 4
• Dosage should be adjusted to produce a resting heart rate of 55-60 beats per minute, provided this is not prevented by side effects 4

Discontinuation warning: If treatment is to be discontinued, reduce dosage gradually over a period of a few weeks to prevent rebound hypertension, tachycardia, or worsening of angina 2, 1

Arrhythmias and Rate Control

For supraventricular arrhythmias requiring acute control, administer propranolol 1-3 mg IV at a rate not exceeding 1 mg/minute, which may be repeated after 2 minutes if necessary, with subsequent doses given at intervals of at least 4 hours. 5

• For chronic oral therapy in arrhythmias, typical dosing ranges from 30-160 mg daily in divided doses 2
• Propranolol is effective for controlling cardiac arrhythmias including supraventricular tachycardias 5
• The drug has membrane-stabilizing properties and is a noncardioselective β-blocker 5

Monitoring Parameters

Monitor heart rate and blood pressure at each visit during titration, with baseline cardiovascular assessment including auscultation before initiating therapy. 2

• Watch specifically for hypotension and bradycardia, especially during dose escalation 2
• Monitor for bronchospasm in patients with any history of reactive airway disease 2
• In diabetic patients, propranolol masks symptoms of hypoglycemia and should be used with extreme caution 2
• No routine blood work (CBC, renal, liver, thyroid function) is required before starting propranolol in otherwise healthy adults 2

Common Adverse Effects

The most frequent side effects include fatigue, bradycardia, hypotension, dizziness, cold extremities, and potential worsening of heart failure 2. Gastrointestinal symptoms, hallucinations, and postural hypotension occur in approximately 8% of patients 6.

Critical Drug Interactions

Avoid routine combination with non-dihydropyridine calcium channel blockers (diltiazem, verapamil) due to increased risk of bradycardia and heart block. 2

• Coadministration with cimetidine increases propranolol AUC and Cmax by 46% and 35%, respectively 1
• Concomitant warfarin administration increases warfarin bioavailability and prothrombin time 1
• Theophylline oral clearance decreases by 30-52% when coadministered with propranolol 1

Formulation Considerations

Extended-release propranolol is not a simple mg-for-mg substitute for immediate-release formulation; retitration may be necessary. 1

• Extended-release formulations have different kinetics and produce lower blood levels than immediate-release tablets 1
• Once-daily extended-release propranolol maintains relatively constant plasma concentrations and clinically significant inhibition of exercise-induced tachycardia throughout a 24-hour dosing interval 7
• The terminal half-life of extended-release propranolol is 8-11 hours compared to shorter half-lives with conventional formulations 7