Collapse cocaine

The cardiovascular effects of local anesthetics result in part from direct effects of these drugs on the cardiac and smooth muscle membranes and from indirect effects on the autonomic nervous system. As described in Chapter 14, local anesthetics block cardiac sodium channels and thus depress abnormal cardiac pacemaker activity, excitability, and conduction. At extremely high concentrations, local anesthetics can also block calcium channels. With the notable exception of cocaine, local anesthetics also depress myocardial contractility and produce direct arteriolar dilation, leading to systemic hypotension. Cardiovascular collapse is rare, but has been reported after large doses of bupivacaine and ropivacaine have been inadvertently administered into the intravascular space. 

Cardiovascular toxicity is also frequently encountered in poisoning. Hypotension may be due to depression of cardiac contractility hypovolemia resulting from vomiting, diarrhea, or fluid sequestration peripheral vascular collapse due to blockade of -adrenoceptor-mediated vascular tone or cardiac arrhythmias. Hypothermia or hyperthermia due to exposure as well as the temperature-dysregulating effects of many drugs can also produce hypotension. Lethal arrhythmias such as ventricular tachycardia and fibrillation can occur with overdoses of many cardioactive drugs such as ephedrine, amphetamines, cocaine, tricyclic antidepressants, digitalis, and theophylline. 

Poisoning can occur with doses of cocaine as low as 20 mg (10 drops of cocaine 4%). Victims generally collapse and die after associated cardiovascular abnormalities, dysrhythmias, and respiratory failure. Signs and symptoms of intoxication include excitement, restlessness, headache, nausea, vomiting, abdominal pain, convulsions, and delirium. 

An 18-year-old man experienced sudden and severe chest pain while drinking alcohol. He vomited, collapsed, and died. On postmortem examination, thrombosis of the left coronary artery, dilated cardiomyopathy with congestive heart failure, and pulmonary embolism were noted. Blood analysis showed raised cocaine and marijuana concentrations and a trace of alcohol. 

---