**12. Sympathomimetic (cocaine) poisoning**

Cocaine is one of the most potent Sympathomimetic, extracted from the leaves of the coca by indigenous to South America; therapeutically, first time Cocaine was used in 1884 as a local anaesthetic for ophthalmologic procedures. In the United States Cocaine is one of the most common causes of acute drug-related emergency department visits.

#### **12.1. Mechanism of action**

Cocaine stimulates alpha and adrenergic receptors by increasing levels of norepinephrine, causing vasoconstriction in cardiovascular system, also inhibits neuronal serotonin reuptake which lead to euphoria. Cocaine blocks Sodium (Na+) channel causing QRS interval prolongation [33, 34].

#### **12.2. Clinical features**

Cocaine toxicity may cause sympathomimetic and vasoconstrictive effects on variety systems (cardiovascular, CNS …etc.).

Cardiovascular: patients with cocaine toxicity present with high blood pressure and dysrhythmias include tachycardia, such as sinus tachycardia, SVT, and AF. ECG changes include rightward shift of the terminal portion of the QRS complex and prolongation the QT interval. Patients may present with acute coronary syndromes (cocaine-associated acute coronary syndrome), aortic and coronary artery dissection, myocarditis and cardiomyopathy. CNS: patients with Cocaine present with a variety CNS clinical features including: agitation, seizures, and coma. Pulmonary: mainly seen in patients who smoke crack cocaine includes pulmonary haemorrhage, barotrauma, pneumonitis and asthma.

Gastrointestinal: Cocaine may cause intestinal ischemia, bowel necrosis and ischemic colitis, also increase risk for bleeding and ulcer perforation. Renal: acute kidney failure may occur because of rhabdomyolysis [35–37].

#### **12.3. Treatment**

Securing the airway and adequate breathing are initial steps in treatment. CNS manifestation (agitation, seizure) treated with sedation by Benzodiazepines, patient with Hyperthermia should be cooled rapidly, severe hypertension not responding to sedation can be treated with a sodium nitroprusside infusion or phentolamine; (avoid Β-ac blockers). Cocaine toxicity with acute coronary syndrome are treated with aspirin and nitroglycerin also may add calcium channel blockers, wide-complex tachycardia with cocaine toxicity treated with serum alkalinisation by sodium bicarbonate, make sure serum Ph do not exceed 7.55. Intravenous lipid emulsion can be used in severe cocaine toxicity, with refractory cardiovascular instability or refractory wide-complex tachycardia [37].
