What is the starting dose of metoprolol (beta blocker) for managing palpitations?

Starting Dose of Metoprolol for Palpitations

For managing palpitations, initiate metoprolol tartrate at 25 mg orally twice daily, which can be titrated up to a maximum of 100 mg twice daily based on symptom control and tolerability. 1

Initial Dosing Strategy

• Start with metoprolol tartrate 25 mg twice daily for symptomatic palpitations, as this provides adequate beta-blockade while minimizing risk of adverse effects 1
• For patients with concerns about beta-blocker tolerance (such as mild reactive airway disease or borderline blood pressure), consider starting even lower at 12.5 mg twice daily 1
• The extended-release formulation (metoprolol succinate) can be initiated at 50 mg once daily if preferred for convenience, with a maximum dose of 400 mg daily 1

Titration Protocol

• Increase the dose gradually every 1-2 weeks if palpitations persist and the patient tolerates the initial dose well 1
• Target a resting heart rate of 50-60 beats per minute unless limiting side effects occur 1
• For metoprolol tartrate, titrate from 25 mg to 50 mg twice daily, then up to the maximum of 100 mg twice daily as needed 1

Critical Contraindications to Screen Before Prescribing

Before initiating metoprolol for palpitations, you must rule out:

• AV block greater than first degree or SA node dysfunction 1
• Decompensated heart failure or signs of low cardiac output 1
• Severe asthma or active reactive airway disease (though mild COPD or history of wheezing is not an absolute contraindication at reduced doses) 1
• Hypotension (systolic BP <100 mmHg) 1
• Cardiogenic shock or risk factors for it 1

Special Considerations for Specific Arrhythmias

If palpitations are due to atrial fibrillation, the dosing is similar but may require higher doses:

• Start with 25-100 mg twice daily of metoprolol tartrate 2, 1
• Alternatively, use metoprolol succinate 50-200 mg once daily for rate control 2
• In acute settings with rapid ventricular response, IV metoprolol 2.5-5 mg over 2 minutes can be given, repeated every 5 minutes up to 15 mg total, then transition to oral therapy 2

Monitoring Parameters

• Check heart rate and blood pressure at each follow-up visit 1
• Watch for symptomatic bradycardia (HR <60 bpm with dizziness) or hypotension (systolic BP <100 mmHg with symptoms) 1
• Listen for bronchospasm, particularly in patients with any history of reactive airway disease 1
• Assess for delayed adverse effects like fatigue or weakness, which may appear within 2-3 weeks 1

Common Pitfalls to Avoid

• Do not abruptly discontinue metoprolol once started, as this can cause severe exacerbation of angina, myocardial infarction, and ventricular arrhythmias 1
• Avoid metoprolol in pre-excited atrial fibrillation (Wolff-Parkinson-White syndrome), as it can paradoxically accelerate ventricular rate by blocking the AV node and facilitating conduction down the accessory pathway 2
• Do not combine with other AV nodal blocking agents without careful monitoring, as profound bradycardia can develop 3
• For patients with mild wheezing or COPD history, use a reduced dose (12.5-25 mg) rather than completely avoiding beta-blockers 1

Expected Outcomes

• Clinical response may be delayed and require 2-3 months to become fully apparent 1
• Most patients with palpitations from benign arrhythmias respond well to doses in the 50-100 mg twice daily range 1
• Note that for idiopathic frequent PVCs, beta-blockers may be less effective, with good response seen in only 11-16% of patients, and paradoxical worsening can occur in up to 25% 4