Alcohol withdrawal syndrome is the set of symptoms seen when an individual reduces or stops alcohol consumption after prolonged periods of excessive alcohol intake. Excessive abuse of alcohol leads to tolerance, physical dependence, and an alcohol withdrawal syndrome. The withdrawal syndrome is largely due to the central nervous system being in a hyper-excitable state. Unlike most withdrawals from other drugs, alcohol withdrawal can be fatal. The withdrawal syndrome can include seizures and delirium tremens and may lead to excito-neurotoxicity.
Chronic use of alcohol leads to changes in brain chemistry especially in the GABAergic system. Various adaptations occur such as changes in gene expression and down regulation of GABAA receptors. During acute alcohol withdrawal, changes also occur such as upregulation of alpha4 containing GABAA receptors and down regulation of alpha1 and alpha3 containing GABAA receptors.Adaptations to the NMDA system also occur as a result of repeated alcohol intoxication and are involved in the hyper-excitability of the central nervous system during the alcohol withdrawal syndrome.
The severity of the alcohol withdrawal syndrome can vary from mild symptoms such as mild sleep disturbances and mild anxiety to very severe and life threatening including delirium, particularly visual hallucinations in severe cases and convulsions
A protracted alcohol withdrawal syndrome occurs in many alcoholics where withdrawal symptoms continue beyond the acute withdrawal stage but usually at a subacute level of intensity and gradually decreasing with severity over time. This syndrome is also sometimes referred to as the post acute withdrawal syndrome.Insomnia is also a common protracted withdrawal symptom which persists after the acute withdrawal phase of alcohol. Insomnia has also been found to influence relapse rate. Studies have found that magnesium or trazodone can help treat the persisting withdrawal symptom of insomnia in recovering alcoholics.