What is the maximum recommended dosage of propranolol (beta blocker)?

Maximum Recommended Dosage of Propranolol

The maximum recommended dosage of propranolol for hypertension is 640 mg per day, though most patients achieve adequate blood pressure control with 120-160 mg daily. 1

Dosage Guidelines by Indication

Propranolol dosing varies significantly based on the specific indication:

Hypertension

• Initial dose: 80 mg once daily (extended-release)
• Maintenance dose: 120-160 mg once daily
• Maximum dose: 640 mg daily 1

Angina Pectoris

• Initial dose: 80 mg once daily (extended-release)
• Typical effective dose: 160 mg once daily
• Maximum dose: 320 mg daily 1

Migraine Prophylaxis

• Initial dose: 80 mg once daily (extended-release)
• Effective dose range: 160-240 mg once daily 1

Infantile Hemangioma

• Starting dose: 1 mg/kg/day in divided doses
• Maintenance dose: 2 mg/kg/day
• Maximum dose for non-responders: 3 mg/kg/day 2

Hypertrophic Subaortic Stenosis

• Usual dosage: 80-160 mg once daily (extended-release) 1

Important Clinical Considerations

Formulation Differences

• Extended-release capsules are not a simple mg-for-mg substitute for immediate-release tablets
• Retitration may be necessary when switching between formulations
• For extended-release formulations, the full hypertensive response may take several weeks 1

Dose Adjustment Factors

• Age: Elderly patients may require lower doses
• Comorbidities: Patients with hepatic or renal impairment may require dose adjustments
• Response: Titrate based on clinical response and heart rate control
• Weight: Pediatric dosing is typically weight-based

Contraindications

1. Hypoglycemic episodes (recent or ongoing)
2. Second or third-degree heart block
3. Hypersensitivity to propranolol
4. Asthma or obstructive airway disease
5. Uncompensated heart failure 2

Monitoring Parameters

• Heart rate (target: 55-60 beats/minute)
• Blood pressure
• Signs of hypoglycemia in at-risk patients
• Cardiac function in patients with heart disease

Special Populations

Pediatric Patients

For children, propranolol dosing is typically weight-based:

• Initial dose: 1 mg/kg/day
• Maximum dose: 4 mg/kg/day up to 640 mg/day 2

Patients with Comorbidities

For patients with conditions that may lead to hypoglycemia, preterm infants, or those with low weight:

• Use more cautious dosing schedules
• Consider starting at 0.5 mg/kg/day
• Individualize dosing regimens under specialist supervision 2

Clinical Pearls

• Sensitivity to propranolol varies widely among patients
• The hypotensive effect often takes 6-8 weeks to reach maximum
• Some patients show a biphasic dose-response curve, with decreased effectiveness at higher doses
• Only about one-third of patients respond adequately to doses ≤160 mg/day; an additional 40% respond to doses between 200-640 mg/day 3
• Abrupt discontinuation should be avoided; gradually taper the dose over several weeks

Remember that while 640 mg is the maximum FDA-approved dose for hypertension, most patients achieve adequate control with much lower doses (120-160 mg daily).