Topic overview

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Ethanol is metabolized mainly by alcohol dehydrogenase, with the microsomal ethanol-oxidizing system becoming more active with chronic intake. Its metabolism depletes NAD⁺, contributing to metabolic disturbances and hepatic fat accumulation. Alcohol-related disease can progress from fatty liver to hepatitis and cirrhosis, with neurological, cardiovascular, pancreatic, hematologic, and fetal consequences. Withdrawal may include delirium tremens. The topic also introduces disulfiram and toxic alcohols, then compares the major effects of stimulants, opioids, nicotine, and cannabis. Examples include stimulant-associated cardiovascular and neurologic emergencies, opioid-related respiratory depression, and memory or coordination impairment with cannabis. Together, these patterns provide a framework for recognizing substance-related injury and understanding key mechanisms.