Makindo Medical Notes

Related Subjects: | Hypertension

Always inquire about cocaine use when relevant, such as in cases of chest pain, haemorrhagic stroke, or trauma (e.g., fights). Note that for cocaine-induced chest pain, unselected beta-blockers alone can cause hypertension due to unopposed alpha effects and should be avoided.

About

• Cocaine is a powerful central nervous system stimulant derived from the leaves of the coca plant. It primarily blocks the reuptake of dopamine, serotonin, and noradrenaline, thereby increasing the levels of these neurotransmitters in the brain.
• Chronic use of cocaine is associated with accelerated atherosclerosis. The euphoric effects of cocaine stem from elevated dopamine levels in the brain’s mesolimbic reward centers.
• Cocaine can be used via snorting, smoking, or intravenous injection. Snorting cocaine allows absorption through the nasal mucosa but can cause significant local vasoconstriction, leading to nasal mucosa damage over time. Smoking and intravenous routes produce a faster but shorter-lasting high. Other methods include rubbing it on gums, taking it orally, or, in rare cases, as a suppository.
• In some medical contexts, cocaine is still used as a local anesthetic in ophthalmic and ENT surgeries due to its dual effect of anesthesia and vasoconstriction, which reduces bleeding.

Clinical

• Chest Pain: Cocaine-induced chest pain is often due to coronary artery spasm, not typically treated with thrombolysis. Cocaine users may have coexisting atherosclerotic disease, which is more susceptible to spasm. Thrombolysis is generally avoided due to the high risk of intracerebral haemorrhage. For persistent ST-elevation, refer for primary PCI (percutaneous coronary intervention) using the STEMI pathway, and consider IV nitrates prior to PCI.
• Hyperthermia: Cocaine use can cause hyperthermia, managed with fluids, cooling, and, if needed, dantrolene. Avoid haloperidol and phenothiazines due to their potential to lower the seizure threshold. Diazepam is preferred for sedation.
• Other Complications: Cocaine use may lead to delirium, hyperthermia, arrhythmias, myocardial infarction, and cerebral infarction. Treatment focuses on ABC (airway, breathing, circulation) management and removing residual cocaine from the nostrils. Toxic effects generally stem from sympathetic stimulation and are short-lived, presenting with symptoms like tachycardia, fever, and hypertension.
• Initial management of cocaine toxicity includes intravenous diazepam to control agitation and body cooling for hyperthermia. Diazepam sedation may also aid in managing hypertension and tachycardia, as excessive sympathetic tone is centrally mediated. When necessary, intravenous nitrate administration is effective in addressing associated coronary artery spasm.

Investigations

• Blood Tests: Check FBC, U&E, and LFTs. Elevated levels of CK may indicate rhabdomyolysis due to hyperactivity or muscle breakdown.
• Cardiac Enzymes: Measure troponin levels to exclude myocardial infarction, especially due to cocaine-induced coronary artery spasm.
• Toxicology Screen: Urine or blood toxicology screens to confirm recent cocaine use and identify co-ingestants, such as alcohol or other drugs that may influence management.
• Electrocardiogram (ECG): Obtain an ECG to identify arrhythmias, prolonged QT intervals, or signs of myocardial ischaemia.
• Imaging: Consider a chest X-ray to rule out pneumothorax, and a CT scan if there is concern for intracranial haemorrhage, particularly in cases of severe headache, altered mental status, or neurological deficits.

Management

• Acute Cocaine Toxicity: Initial management focuses on airway, breathing, and circulation (ABC). Sedation with benzodiazepines, such as IV diazepam or lorazepam, is often the first step to manage agitation, anxiety, and hyperthermia.
• Cardiovascular Complications:
  • Hypertension and Tachycardia: Benzodiazepines can help control sympathetic overdrive. Avoid beta-blockers as they can worsen hypertension by allowing unopposed alpha-adrenergic activity.
  • Chest Pain: Administer nitrates or calcium channel blockers for chest pain associated with coronary artery spasm. Intravenous nitrates, such as nitroglycerin, are preferred over beta-blockers.
• Hyperthermia: Immediate cooling measures, such as IV fluids, external cooling blankets, and, if necessary, dantrolene for refractory hyperthermia. Avoid phenothiazines and antipsychotics as they can lower the seizure threshold.
• Rhabdomyolysis: Manage with aggressive IV hydration to prevent kidney damage. Monitor CK levels and renal function regularly.
• Long-Term Management:
  • Psychosocial Support and Rehabilitation: Refer the patient to addiction treatment services for counseling and behavioral therapy.
  • Follow-Up: Regular follow-ups with mental health and addiction specialists. Monitoring of cardiovascular health is also recommended for long-term users due to the risk of atherosclerosis.