Final answer:
After first pass metabolism of alcohol is complete, ethanol has been converted into acetaldehyde in the liver. The rate of alcohol metabolism varies per individual and is slower in women than men. Sobriety after legal intoxication typically takes at least five hours, as the liver needs time to metabolize the alcohol.
Step-by-step explanation:
When considering the person who has been drinking some alcohol, once first pass metabolism is complete, ethanol has been converted into acetaldehyde by the enzyme alcohol dehydrogenase in the liver. This process uses nicotinamide adenine dinucleotide (NAD) as a co-factor to accept the electrons and hydrogen transferred during the oxidation of ethanol, producing NADH in the process. The rate at which alcohol is metabolized can vary significantly among individuals; for instance, women generally metabolize alcohol more slowly than men. The eventual metabolism of ethanol leads to its breakdown and elimination from the body. It is important to note that this metabolic process is not accelerated by interventions like drinking coffee or taking a shower.
The only way to effectively manage blood alcohol levels and avoid alcohol toxicity is to allow the liver enough time to process the ingested ethanol. With average metabolism rates it takes about 2.5 hours for a 70 kg person to oxidize the alcohol contained in a standard drink. For legally intoxicated individuals sobriety is typically attained after at least five hours as the body continues to metabolize and excrete alcohol at a constant rate until its concentration reaches nearly zero. The metabolic system responsible for this is not only the alcohol dehydrogenase pathway but also the microsomal ethanol oxidizing system (MEOS), which becomes more active during periods of heavy drinking. Chronic excessive alcohol use can lead to long-term health consequences, particularly affecting the liver and kidneys, which are essential organs in the excretory system responsible for eliminating waste products.