Circulation

Treatment for hypertension

Treat cocaine-associated hypertension initially with titrated intravenous benzodiazepines (see Sympathomimetic toxidrome / Sedation). Intravenous benzodiazepines may also relieve cocaine-associated chest pain and acute coronary syndromes. Antihypertensive drugs are rarely required, but if hypertension does not respond to treatment with intravenous benzodiazepines, use an intravenous glyceryl trinitrate infusion (see Sympathomimetic toxidrome / Treatment for hypertension and tachycardia). Discuss the use of other antihypertensives with a clinical toxicologist.

Treatment for chest pain and acute coronary syndromes

Cocaine-associated chest pain can be secondary to acute coronary artery spasm or accelerated atherosclerosis. In patients with chest pain, commence continuous ECG monitoring, and 6-hourly 12-lead ECGs and serum troponin concentrations, to exclude an acute coronary syndrome.

Cocaine-associated chest pain may resolve with titrated intravenous benzodiazepines for agitation or hypertension (see Sympathomimetic toxidrome / Sedation).

Manage cocaine-associated acute coronary syndrome according to standard acute coronary syndrome treatment guidelines with the following caveats:

• administer aspirin 300 mg orally
• treat chest pain or myocardial ischaemia that does not respond to intravenous benzodiazepines with glyceryl trinitrate (see Sympathomimetic toxidrome / Treatment for hypertension and tachycardia)
• beta blockers are contraindicated because they can worsen vasoconstriction via unopposed alpha-adrenergic agonist effects
• calcium channel blockers should only be used if other therapies have failed
• if there is clear evidence of ST elevation myocardial infarction (STEMI) on ECG, the preferred reperfusion strategy is percutaneous coronary intervention (PCI). Thrombolytic therapy should only be considered if:
  • PCI is not available
  • there are no contraindications to thrombolytic therapy.

Treatment for QRS widening and sodium channel blockade

If there is evidence of QRS widening on ECG, commence continuous ECG monitoring and assess serial 12-lead ECGs, and manage urgently according to Treatment for QRS widening and sodium channel blockade: serum alkalinisation.

If serum alkalinisation with sodium bicarbonate does not resolve arrhythmias associated with QRS widening (eg ventricular tachycardia), lidocaine may be used as an alternative antiarrhythmic drug—consult a clinical toxicologist.

Although amiodarone is commonly used for ventricular tachycardia, there is no evidence to support its use for cocaine poisoning and it is not recommended.

Inotropic support

For cardiovascular collapse due to cocaine poisoning, start inotropic support with noradrenaline (norepinephrine) (see Noradrenaline (norepinephrine) intravenous infusion instructions for advice on preparation and administration). Bedside echocardiography is useful to determine the relative contributions of negative inotropy and vasodilation to hypotension, and hence guides treatment choice—discuss further management with a clinical toxicologist.