Alcohol

Alcohol is one of the most commonly abused substances in the world and in the US, at least 67% of the population consumes alcohol. 14% of men and 4% of women are heavy drinkers. The lifetime prevalence for alcohol dependence or abuse is about 14%. It is estimated that 25% of general hospital inpatients have an alcohol-related disorder.

Use & abuse

Just a quick reminder that abuse is the harmful use of a substance. Misuse is the prescription of a drug for something outside of accepted medical practice. Addiction is impaired control over the use of a substance. Dependence is a physical state of adaptation that manifests as a withdrawal syndrome. Psychological dependence is the feeling of need for a substance to avoid negative effects associated with abstinence from it.

Consumption

With normal liver function and body fat, you can expect the BAL to decrease approximately 0.02 per hour. Or, put another way, one drink raises one's BAL about 0.02 and the body metabolizes alcohol at the rate of one drink per hour (this rate is also dependent on body mass). Note that we usually measure BAL in grams/deciliter, but some institutions use milligrams/deciliter and so you would see a fall of 20 mg/dL in an hour. Interestingly, first pass metabolism of alcohol is often lower in females because of a decreased level of gastric alcohol dehydrogenase. This could explain the lower thresholds for intoxication among women.

Indices of alcohol use

There is no highly reliable index of alcohol use, but serum gamma -glutamyltransferase levels are elevated in over half of patients who have alcohol use disorders. Aspartate amino-transferase (AST) is elevated in slightly under half.

Medical complications

Chronic alcohol use is related to a variety of medical conditions including gastric & peptic ulcers, pneumonia, hepatitis, pancreatitis. cardiomyopathy, hemorrhagic stroke, hypertension, anemia, and alcoholic dementia. It has been estimated that up to 75% of pancreatitis patients are alcohol dependent. Alcoholism is also associated with a 60-120 fold increase in the risk of suicide.

Several medications have otable interactions notable interactions with alcohol.

Withdrawal & tolerance

Withdrawal is a specific group of signs or symptoms that appear after alcohol use ceases. Alcohol (and benzodiazepine) withdrawal should be treated aggressively as it can result in death. Sever cases of alcohol withdrawal can be associated with delirium, psychosis, anxiety, and sleep disorders.

Tolerance in alcohol dependent patients can be quite remarkable. It is not unusual to see a chronic alcoholic in the emergency room with a BAL of .4. This level could be lethal for an alcohol-naïve patient, but the chronic alcoholic can be conversant and oriented to person, place, and time. Importantly, the lethal dose of alcohol is relatively unchanged even with tolerance. Thus, a BAL of .5 is lethal in approximately half of patients. Initial signs of alcohol toxicity are unresponsiveness, shallow breathing, and cardiac arrhythmia.