Cocaine. Computer graphic model of a molecule of the drug cocaine (benzoylmethylecgonine). It has the chemical formula: C17.H21.NO4. Here, atoms are depicted as spheres, and are colour-coded: carbon (green), hydrogen (yellow), oxygen (blue), nitrogen (lilac). Cocaine is an alkaloid drug obtained from leaves of the coca plant Erythroxylon coca. It can be smoked, injected, or snorted. This drug stimulates the central nervous system to produce feelings of exhilaration and energy. Prolonged use of cocaine leads to anxiety, paranoia and psychological dependency. Overdose can result in cardiac arrhythmia and death.