Is Valium (diazepam) effective for controlling heart rate, specifically tachycardia?

Diazepam (Valium) is Not Effective for Controlling Heart Rate in Tachycardia

Diazepam (Valium) is not recommended for controlling heart rate in tachycardia, as there are multiple established first-line medications with proven efficacy and safety profiles for this purpose. 1

Established Medications for Heart Rate Control

First-Line Agents for Tachycardia Management:

• Beta blockers (metoprolol, atenolol, esmolol) are recommended as first-line therapy for rate control in most tachycardias including atrial fibrillation and supraventricular tachycardia 1
• Non-dihydropyridine calcium channel blockers (diltiazem, verapamil) are equally effective first-line agents, particularly useful in patients with contraindications to beta blockers 1
• For acute treatment of multifocal atrial tachycardia, intravenous metoprolol or verapamil are specifically recommended 1

Second-Line Agents:

• Digoxin is effective for controlling resting heart rate, particularly in patients with heart failure 1
• Amiodarone can be useful when other measures are unsuccessful or contraindicated 1
• Sotalol or dofetilide may be reasonable for specific tachyarrhythmias when first-line agents fail 1

Evidence Against Diazepam for Heart Rate Control

While diazepam has been studied for its cardiovascular effects, the evidence does not support its use for controlling tachycardia:

• Diazepam may actually increase heart rate in some patients through vagolytic effects 2, 3
• Studies show diazepam can produce variable hemodynamic effects, including potential increases in heart rate relative to placebo 4, 3
• Benzodiazepines like diazepam may suppress cardiac vagal tone, which could theoretically worsen tachycardia 2
• Current cardiology guidelines do not include diazepam among recommended agents for rate control in any form of tachycardia 1

Important Considerations and Contraindications

When selecting rate control medications, several important contraindications must be considered:

• Pre-excited atrial fibrillation: Patients with pre-excitation syndromes (WPW) should not receive AV nodal blocking agents like beta blockers, calcium channel blockers, or digoxin as these may enhance conduction over accessory pathways and potentially precipitate ventricular fibrillation 1
• Heart failure: Calcium channel blockers should be avoided in decompensated heart failure 1
• Bronchospasm: Beta blockers should be used cautiously in patients with reactive airway disease 1

Recommended Approach to Tachycardia Management

1. Identify the specific tachyarrhythmia through 12-lead ECG 1
2. Assess hemodynamic stability - unstable patients require immediate electrical cardioversion 1
3. For stable patients, select appropriate pharmacological therapy:
   • For SVT/AF/Flutter: Beta blockers or calcium channel blockers as first-line 1
   • For pre-excited AF: Avoid AV nodal blockers; consider procainamide or ibutilide 1
   • For multifocal AT: Verapamil or metoprolol 1
4. Consider catheter ablation for recurrent symptomatic tachycardias refractory to medical therapy 1

In conclusion, diazepam has no established role in controlling heart rate in tachycardia, and its use for this purpose is not supported by current evidence or guidelines. Clinicians should instead rely on proven rate-control medications such as beta blockers and calcium channel blockers.