Alkohol

Abstract

Alcohol (ethyl alcohol, ethanol) is central nervous system depressant, antibacterial agent and solvent. Because it is the second most widely used psychoactive substance in the world (after caffeine), alcohol has created special problems for both individual users and society in general. Alcohol is rapidly and completely absorbed from the entire gastrointestinal tract. After absorption, it is evenly distributed throughout all body fluids and tissues. The blood-brain barrier and placenta are freely permeable to alcohol. Approximately 95% of the ingested alcohol is enzymatically metabolized by alcohol and aldehyde dehydrogenases to water and carbon dioxide, thus releasing energy. Other than providing calories, alcohol has no nutritional value. The primary pharmacological effect of alcohol is reversible depression of CNS. A unitary hypothesis, where one single neurochemical effect can explain all of alcohol's actions, may not be possible at all. It is known that drug dissolves in cell membranes nonspecifically and indirectly altering membrane processes. Alcohol is a GABA and dopamine agonist. On the other hand it acts as acetylcholine and N-methyl-D-aspartate receptor (NMDA) antagonist. Alcohol influences on respiration. It exerts a diuretic effect, interferes with sexual performance and dilates the blood vessels in the skin. Long-term use of alcohol is associated with diseases of the heart muscle, but low doses consumed daily may reduce the risk of coronary artery disease. The behavioral effects of alcohol are unpredictable and are determined by the person and the environment. In one setting a person may become relaxed or euphoric and in another violent. Alcohol causes incoordination, concentration and cognition problems. Long-term ingestion of larger amount of alcohol produces variety of serious neurological, mental and physical disorders and vitamin and trace element deficiencies. Alcohol is clearly delineated teratogen and a major risk factor for cancer. Chronic use of alcohol leads to the development of tolerance, physical and psychological dependence called alcoholism. Contemporary alcoholism treatment is an combination of medical, psychological, psychosocial, and spiritual modalities interacting in a quasi- organized framework to assist the individual in achieving and sustaining lasting sobriety. For treating alcoholism the following drugs could be used: disulfiram (alters the metabolism of alcohol, allowing acetaldehyde to accumulate, making the patient extremely uncomfortable), benzodiazepines and antidepressants (management of withdrawal syndrome), naltrexone (a long- lasting orally administered narcotic antagonist which reduces alcohol craving and relapse), fluoxetine (reduces daily alcohol intake in persons in the early stages of alcoholism), and emetics combined with alcohol (conditioned- avoidance techniques - patient associates the drinking of alcohol with nausea and vomiting caused by emetics). Finally, haloperidol and other antipsychotic agents are useful in the treatment of hallucinations associated with severe delirium tremens.