Cocaína: Aspectos farmacológicos

Abstract

The routes of administration of cocaine are different depending on the cocaine source (leaves, sulphate, hydrochloride and crack), and this affects not only its pharmacokinetics but also its pharmacological effects, as well as other aspects such as toxicity, tolerance, dependence and withdrawal effects of this drug. In our country, cocaine is mainly smoked or inhaled, and intravenous administration can be also used. Cocaine is rapidly absorbed by many routes. Cocaine produces central effects in 30 seconds after nasal or intravenous administration and in only 5 seconds when cocaine is smoked. The major route for cocaine metabolism involves hydrolysis of its ester groups producing benzoylecgonine, ecgonine methyl ester and ecgonine as metabolites. An important metabolic interaction occurs when cocaine and alcohol are taken concurrently; cocaine is then transesterified to cocaethylene, which is toxic. Cocaine is a potent inhibitor of catecholamine uptake by noradrenergic, dopaminergic and serotoninergic nerve terminals and strongly enhances the effects of these neurotransmitters. Pharmacological and toxic effects are derived from its actions on the catecholaminergic system.