**1.2. Alcohol metabolism and distribution**

Alcohol is absorbed in the stomach and intestines through the blood stream and crosses the blood-brain barrier (BBB) after consumption. Alcohol is metabolized through the mitochondrial cytochrome P450 (CYP2E1) and catalase in the liver or the brain. In the brain, alcohol metabolism by CYP2E1 produces acetaldehyde and alcohol is considered to be the only source of acetaldehyde. The rest of the acetaldehyde may go through the brain by an enzyme called alcohol dehydrogenase (ADH) which is found in the liver and helps in conversion of alcohol to acetaldehyde. Target of alcohol is considered to be ADH. Alcohol binds through its hydroxyl (─OH) group and zinc atom on ADH [1]. Disulfiram (antabuse), one of the first approved treatments for alcoholism, showed its mechanism by inhibiting the ADH enzyme. When taken regularly, disulfiram decreases the drinking capacity because of the aversive effects [2].
