What is a safe tablet for an adult patient with palpitations and no history of asthma or chronic obstructive pulmonary disease (COPD)?

Safe Tablet for Palpitations in Adults Without Asthma or COPD

For an adult patient with palpitations and no history of asthma or COPD, metoprolol is the safest and most effective oral tablet option, with typical dosing starting at 25-50 mg twice daily and titrating up to 100 mg twice daily as needed for symptom control. 1

First-Line Recommendation: Beta Blockers

Oral metoprolol is the preferred agent for managing palpitations from supraventricular tachyarrhythmias in patients without contraindications 1. The evidence supporting this recommendation includes:

• For AVNRT (most common SVT): Oral beta blockers are reasonable for acute treatment in hemodynamically stable patients and are Class IIb recommendation 1
• For multifocal atrial tachycardia: Metoprolol is reasonable for ongoing management (Class IIa, Level C-LD) 1
• Clinical efficacy: In patients with MAT and serious pulmonary disease, oral metoprolol (25-50 mg) restored sinus rhythm in all 11 patients within 1-3 hours without adverse effects 2

Dosing Strategy

Start with metoprolol tartrate 25-50 mg twice daily 1, 3. The dose can be titrated up to 100 mg twice daily for maintenance therapy based on symptom control and heart rate response 1. For extended-release formulations, metoprolol succinate 50-400 mg daily or in divided doses is appropriate 1.

Alternative Options: Calcium Channel Blockers

If beta blockers are not tolerated or contraindicated, oral verapamil or diltiazem are reasonable alternatives:

• Verapamil: 180-480 mg daily (extended release) for rate control 1
• Diltiazem: 120-360 mg daily (extended release) for rate control 1

These agents are particularly useful for:

• AVNRT: Oral verapamil or diltiazem may be reasonable for acute treatment (Class IIb) 1
• MAT: Oral verapamil (Class IIa, Level B-NR) or diltiazem (Class IIa, Level C-LD) are reasonable for ongoing management 1
• Atrial flutter: Oral diltiazem or verapamil are useful for rate control (Class I) 1

Critical Safety Considerations

Absolute Contraindications to Beta Blockers

• Asthma (COPD is NOT a contraindication) 1
• Second- or third-degree heart block without pacemaker 1
• Sick sinus syndrome without pacemaker 1
• Sinus bradycardia <50 bpm 1

Contraindications to Calcium Channel Blockers

• Avoid verapamil and diltiazem in:
  • Heart failure with reduced ejection fraction (HFrEF) 1
  • Severe conduction abnormalities 1
  • Sinus node dysfunction 1
  • Pre-excitation syndromes 1

Common Pitfalls to Avoid

Do not avoid beta blockers in COPD patients - this is a common misconception. Metoprolol is relatively cardioselective (beta-1 selective) and has been safely used in patients with serious pulmonary disease after correction of hypoxia 1, 2. However, beta blockers should be avoided during acute respiratory decompensation or in patients with bronchospasm 1.

Monitor for hypotension - this is the major potential side effect of both beta blockers and calcium channel blockers, particularly with verapamil 1. Symptomatic hypotension often improves with time, and patients should be reassured 1.

Clinical Context Matters

The specific arrhythmia causing palpitations influences treatment choice:

• For focal atrial tachycardia: IV beta blockers, diltiazem, or verapamil are Class I recommendations for acute treatment 1
• For junctional tachycardia: Oral beta blockers are reasonable for ongoing management (Class IIa) 1
• For atrial fibrillation: Multiple rate control options exist, with metoprolol 25-200 mg twice daily being standard 1

The key advantage of metoprolol over calcium channel blockers is its safety profile in patients with structural heart disease and its lack of exacerbation of pulmonary disease 1, making it the optimal first-line choice for most patients with palpitations who do not have asthma.