Pulmonary Effects of Cocaine Use

Cocaine is an alkaloid found in the leaves of Erythroxylon coca, commonly known as coca. Erythroxylon coca is a native plant of the Andean and Amazon regions in South America. In the mid19th century the inhabitants of the Andes chewed the leaves to ward off fatigue, hunger and thirst, to enhance endurance, and to promote a sense of wellbeing. Cocaine was used as a local anesthetic in eye, ear and throat surgery [1]. Cocaine is a powerful central nervous system stimulant and has very complex activity, both through central and peripheral pathways. The local anesthetic properties of cocaine derive from its ability to stabilize cell membranes and block neuronal sodium channels. It also has potent sympathomimetic and central nervous system stimulant effects due to interference with the reuptake of catecholamines and serotonin thereby preventing nervous transmission [2,3]. Cocaine is sold on the street, mixed with similar-looking substances like lidocaine, talcum powder or sugar. Cocaine is generally consumed in freebase form or smoked as “crack”. It can be absorbed via intranasal, intravenous or vaginal routes in the hydrochloride form or by massaging the gums in coca paste form (prepared using solvents like kerosene and gasoline). It can be smoked either in pipes or cigarettes [1]. Cocaine hydrochloride is a heat-labile fine white powder that can be inhaled nasally or injected intravenously but cannot be smoked. Freebase, a lipidsoluble, heat-stable, form that can be smoked is produced from cocaine hydrochloride. When Cocaine hydrochloride is boiled in water and baking soda, it forms a precipitate which is filtered or extracted with ether or alcohol into an irregular crystal which is the freebase form. The free base form looks like a rock thus commonly called the rock. When the rock is heated, it makes a characteristic “crack” sound thus it is also known as crack [47]. “Crack lung” refers to a syndrome of diffuse alveolar damage and hemorrhagic alveolitis that occurs within 48 hours of crack cocaine use. It is characterized by acute respiratory symptoms like shortness of breath or cough. Crack lung is associated with diffuse alveolar hemorrhage or occasionally eosinophilia on bronchoscopy. Diffuse alveolar damage and hyaline membrane formation is commonly found in biopsy or autopsy specimens of cocaine users who present with crack lung [8-10]. In this article, we discuss the common effects of cocaine to the lungs and emphasize on the need for a thorough history in the diagnosis of the effects of cocaine to the lungs. Most of the patients present with common signs and symptoms that could be found in other medical conditions, but the key to the correct diagnosis is in a thorough history.