Name: Ethanol
Class: Alcohol
Mechanism: Disordering of lipid memb. ® perturbs fxns of ion-channels & other proteins. May augment GABA med. synaptic inhib & Cl- influx. High conc ® Cl- permeability w/o GABA mediation.
Absorption: Rapidly, and usu. completely, absorbed from mouth, stomach, small intestine.
Dist.: Rel. uniform distribution throughout all tissues and fluids.
Metabolism.: 90-98% completely oxid. Zero order kinetics: 7-15 gram (1 drink)/hr. Mostly oxid. in liver by alcohol dehydrogenase. Resulting acetaldehyde oxid by mitoch. aldehyde dehydrog.
Excretion, t½: 2-10% not oxidized (excreted via lungs and kidneys).
Tox./S.E.s: CNS—depressant (additive w/other depressants); Heart—¯ contractility, arrhythmia; Smooth Musc—vasodilation. May inhib. Metabolism. of other drugs. Resp. depression, hypoglycemia.
Chronic S.E.s: Liver/GI—liver fat accum, hepatitis, fibrosis, cirrhosis; gastric & pancreatic secretion & mucosal damage ® risk of gastritis and pancreatitis, aggravation of PUD. Nerv. sys—symm. periph. nerve injury, memory loss, sleep disturbances, psychoses. Blood—mild anemia (¯ prolif. of marrow cells), HDL/LDL ratio (¯ risk of CHD). CV—cardiomyopathy, arrhythmia. Fetal Alcohol Synd. Sex—impotence, sterility, testicular atrophy, gynecomastia, ¯ estrogen Metabolism. Cancer risk—mouth, pharynx, larynx, esophagus, liver, breast. Alcohol W/drawal Synd.
Utility: Solvent for drug admin., nerve blocking agent for pain relief, antidote for methanol and ethylene glycol poisoning.
Special Features: Induces cyt. P450. Acute tolerance can occur.