Alcohol metabolism occurs through several steps, beginning with ethanol (alcohol), proceeding through acetaldehyde, and ending with acetate (acetic acid), which can be excreted in the urine. First, ethanol or alcohol can be metabolized to acetaldehyde in 3 ways. The first and most important way is through alcohol dehydrogenase in the cytoplasm, which is blocked by the drug, fomepizole. Alcohol dehydrogenase operates via zero-order kinetics, which means that it happens at a constant rate regardless of how much alcohol you drink. Less important paths include CYP2E1 in the microsome, or catalase in the peroxisome. The acetaldehyde is then metabolized into acetate through the actions of aldehyde dehydrogenase. The drug disulfiram is given to discourage drinking, as it blocks aldehdye dehydrogenase and leads to the build-up of the toxic intermediate: acetaldehyde. Finally, the metabolism of alcohol usually generates 2 molecules of NADH from NAD+, which increases the NADH to NAD+ ratio. The increase in this ratio leads to a number clinical findings, such as lactic acidosis, fasting hypoglycemia, hepatosteatosis, and ketogenesis.