What is the treatment for cocaine-induced tachycardia?

Treatment of Cocaine-Induced Tachycardia

Benzodiazepines are the first-line treatment for cocaine-induced tachycardia, as they address the underlying central nervous system stimulation driving the sympathetic surge. 1, 2

Initial Management Approach

Start with benzodiazepines immediately to reduce sympathetic nervous system activation, which is the primary driver of cocaine-induced tachycardia and hypertension. 1, 2

• Administer lorazepam 2-4 mg IV or diazepam 5-10 mg IV as first-line therapy 2
• Benzodiazepines control agitation, reduce central nervous system stimulation, and often resolve tachycardia without additional agents 1, 3
• The American Heart Association guidelines classify benzodiazepines as Class IIa (beneficial) for cocaine-induced cardiovascular toxicity 1

If Tachycardia Persists After Benzodiazepines

If severe tachycardia continues despite adequate benzodiazepine dosing, consider adding vasodilators rather than beta-blockers:

Vasodilator Options (in order of preference):

• Phentolamine (α-blocker): 5 mg IV bolus, repeat every 10 minutes as needed for catecholamine-excess states 2
• Calcium channel blockers (verapamil or nicardipine): Effective for both tachycardia and hypertension without the risks of beta-blockade 1, 3
• Nitroglycerin: Start at 5 mcg/min, increase by 5 mcg/min every 3-5 minutes (maximum 20 mcg/min), particularly useful if concurrent chest pain 2

Combined α/β-Blockers (Use with Extreme Caution):

• Labetalol or carvedilol may be considered ONLY after vasodilator therapy has been established 1, 2, 3
• The American College of Cardiology emphasizes that combined α/β-blockers should only be used after alpha blockade or vasodilation is achieved 2

Critical Safety Warnings

Absolute Contraindication: Pure Beta-Blockers

Never use pure beta-blockers (propranolol, metoprolol, esmolol) in cocaine toxicity. 1, 4, 5

• Pure beta-blockade causes unopposed alpha-adrenergic stimulation, worsening coronary vasospasm and hypertension 1, 4, 5
• A fatal case report documented death following metoprolol administration for cocaine-associated chest pain and tachycardia 4
• Animal studies demonstrate that beta-blockers exacerbate cocaine-induced lethality 4
• The FDA label for metoprolol warns against use in pheochromocytoma without prior alpha blockade, a principle that applies to cocaine's catecholamine excess 6

Special Circumstance: Wide-Complex Tachycardia

If cocaine causes wide-complex tachycardia (due to sodium channel blockade, similar to Class Ic antiarrhythmics):

• Administer sodium bicarbonate 1 mL/kg of 8.4% solution IV bolus, repeat as needed until QRS narrows to <120 ms 1, 7
• This approach is extrapolated from treatment of tricyclic antidepressant and Class Ic drug toxicity 1
• Lidocaine's role remains unclear; current evidence neither supports nor refutes its use 1

Evidence Quality and Limitations

The American Heart Association acknowledges that treatment strategies are extrapolated from acute coronary syndrome studies, small case series, and experiments in cocaine-naïve volunteers rather than high-quality randomized trials. 1 A 2016 systematic review involving 2,358 subjects found that benzodiazepines had only 8 treatment failures across multiple studies, supporting their safety and efficacy. 3

No single agent has been proven superior to another for cocaine cardiovascular toxicity (Class IIb evidence), so clinical judgment based on the specific presentation guides agent selection. 1

Monitoring Considerations

• Continuously monitor cardiac rhythm and vital signs 2
• Cocaine's effects are transient; carefully titrate medications to avoid hypotension after cocaine metabolism 1
• Watch for severe bradycardia if any beta-blocking agent is used 6
• Consider medical toxicology consultation for severe cases 1