Few people realize the interaction cocaine has with alcohol. Enough people may realize that cocaine is a stimulant while alcohol is a depressant and avoid mixing them for that reason, but really it goes beyond this.
Cocaine is benzoylmethylecgonine, and alcohol is ethanol aka ethyl alcohol. When a person uses alcohol in conjunction with cocaine what actually happens is another drug is formed within your body. Your body, without alcohol, has a mechanism by which it breaks cocaine down into two inactive metabolites (benzoylecgonine and ecgonine methyl ester). However, with alcohol present a portion of the cocaine will instead turn into cocaethylene, which is the ethyl ester of benzoylecgonine.
Cocaethylene lasts longer than cocaine in the body. It's a triple re-uptake inhibitor (SNDRI); with greater affinity for the dopamine transporter than cocaine, but a lesser affinity for serotonin and nor-epinephrine transporters. Many find it to be more euphoric than cocaine but it may also be more dangerous (cardiotoxic).
Toxicity is of concern regarding cocaine. Even though it is apparently more socially acceptable to use cocaine than many other 'hard' illicit substances, cocaine really isn't the best thing to be putting in your body. A lot of the coke and crack heads I've known, for example, seemed to think heroin was disgusting and physically more dangerous. Fact of the matter is that cocaine can be quite toxic to your major bodily organs. It anesthetizes cardiac cells, which isn't a good thing. Think of the numbing effect it has on your tongue, throat, gums and mucous membranes... well that's what it is doing to your heart muscles as well. It may potentially be toxic to other organ systems as well such as your muscles, liver and kidneys. Idiosyncratic [rare, fatal] reactions can occur. Cocaine isn't neurotoxic, though.
LOL have fun 
