acute cocaine hydrochloride poisoning

Symptoms

An overdose of cocaine is an accelerated version of the classic physiological and psychological responses to cocaine use. Initial euphoria is followed by excitability, delirium, tremors, convulsions, tachycardia, and angina pectoris, all of which are signs of overwhelming sympathetic stimulation of the brain, heart, and lungs. Death is usually caused by a cardiovascular event or to respiratory failure. Plasma and liver pseudocholinesterase detoxify cocaine into water-soluble metabolites that are excreted in urine. Anyone with low plasma cholinesterase activity (such as a fetus, infant, pregnant woman, or someone with liver disease) is very prone to cocaine toxicity. People who congenitally lack pseudocholinesterase are highly sensitive to the effects of any dose of cocaine.

Many chronic cocaine users overdose while taking no more than their usual amount of the drug, when, e.g., the purity (pharmacological strength) of an ingested dose is greater than usual or the drug has been mixed with another psychoactive substance. Lethal overdoses are usually caused by acute coronary syndromes. Some cocaine users may die instead of intracerebral hemorrhage. The presenting findings may include seizures, hemiplegia, aphasia, or coma. Patients admitted for trauma may also be cocaine intoxicated (two thirds of cocaine-related deaths result from traumatic injuries, not drug overdose). Because many signs and symptoms that cocaine produces resemble those from injuries, and because cocaine poisoning is life-threatening, emergency department care providers must quickly distinguish drug-related problems from traumatic injury problems.

Treatment

Oxygen and aspirin should be given with benzodiazepines to reduce agitation and calcium channel blockers to reduce high blood pressure. Beta blockers should be avoided.

Patient care

Vital signs are checked frequently, the patient is attached to a cardiac monitor, and an intravenous line is initiated. Large volumes of fluids are infused to help remove protein breakdown products from the body (a result of rhabdomyolysis). Bilateral lung sounds are auscultated frequently during fluid resuscitation because aggressive fluid therapy can worsen heart failure. Care providers try to physically control patients to prevent them from injuring themselves. If patients demonstrate violent or aggressive behavior, chemical or physical restraints may be necessary. Calcium channel blockers or a benzodiazepine is administered as prescribed to reduce the patient's blood pressure and heart rate. Seizures, which occur because the seizure threshold is lowered by cocaine, are treated with diazepam. Because cocaine causes hypothalamic thermal regulatory dysfunction, core body temperature must be monitored closely. Elevated temperature is treated with acetaminophen and cooling blankets, cool-air ventilation, and cool saline gastric lavage. Central Nervous System (CNS) stimulation may be followed by CNS depression (flaccid paralysis, coma, fixed and dilated pupils, respiratory failure, and cardiovascular collapse).

Cocaine smuggling often involves body packing (swallowing balloons, condoms, or other objects filled with cocaine). If these items leak, the patient becomes intoxicated and is at high risk for death.

If the patient survives the acute poisoning episode, treatment is directed toward helping the patient abstain from drugs and preventing relapses. The patient benefits from consultation with an addictions specialist or mental health nurse practitioner. Studies support the effectiveness of a 12-step program, such as Cocaine Anonymous, to help build a solid recovery program. Other community resources also can be accessed to provide various types of support and to help the patient identify and manage relapse triggers.