Alcohol withdrawal syndrome: how to predict, prevent, diagnose and treat it.

(1) When people who are physically dependent on alcohol stop drinking, they experience an alcohol withdrawal syndrome. The symptoms generally resolve spontaneously within a week, but more severe forms may be associated with generalised seizures, hallucinations and delirium tremens, which can be fatal. (2) We carried out a literature review in order to obtain answers to the following questions: how to predict or rapidly diagnose a severe alcohol withdrawal syndrome; how to prevent and treat this syndrome; how to manage severe forms; and how to deal with the risk of vitamin B1 deficiency. (3) The main risk factors for severe withdrawal syndrome are: chronic heavy drinking; a history of generalised seizures; and a history of delirium tremens. (4) Anxiety, agitation, tremor, excessive sweating, altered consciousness and hallucinations are signs of a severe withdrawal syndrome. (5) Individual support and effective communication seem to reduce the risk of severe withdrawal syndrome. (6) Oral benzodiazepines are the best-assessed drugs for preventing a severe alcohol withdrawal syndrome, particularly the risk of seizures. When given for a maximum of 7 days, the adverse effects are usually mild. (7) Clinical trials of other antiepileptics suggest they are less effective than benzodiazepines, and their addition to benzodiazepine therapy offers no tangible advantage. (8) Betablockers increase the risk of hallucinations, and clonidine increases the risk of nightmares, and the efficacy of these two drugs is not well documented. Neuroleptics increase the risk of seizures. There are no convincing data to support the use of magnesium sulphate or meprobamate (the latter carries a risk of serious adverse effects). Acamprosate, naltrexone and disulfiram are not beneficial in alcohol withdrawal. (9) Gradual withdrawal, i.e. ingestion of decreasing amounts of alcohol, has not been compared with other methods but is generally not recommended. (10) There are no specific recommendations on hydration. Note that excessive water-sodium intake carries a risk of pulmonary oedema in patients with heart disease. (11) As vitamin B1 deficiency is frequent and can lead to serious complications in alcohol-dependent patients, oral vitamin B1 supplementation is widely recommended, despite the absence of comparative trials. High doses must be used to compensate for poor absorption. Intravenous administration is best if patients have very poor nutritional status or severe complications such as Gayet-Wernicke encephalopathy (a medical emergency), even though rare anaphylactic reactions have been reported after vitamin B1 injection. (12) Planned alcohol withdrawal in specialised hospital units has been extensively studied. Outpatient withdrawal may be more appropriate for patients who are at low risk of developing severe withdrawal syndrome. (13) A large proportion of alcohol-dependent patients were excluded from trials of withdrawal strategies. These include elderly patients, patients with serious psychiatric or somatic disorders, and patients who are also dependent on other substances. (14) An oral benzodiazepine is the best-assessed treatment for a single episode of generalised seizures or hallucinations during alcohol withdrawal. (15) In randomised comparative trials benzodiazepines were more effective than neuroleptics in preventing delirium-related mortality. Currently, with appropriate fluid-electrolyte support, continuous monitoring of vital signs, and respiratory support if necessary, the mortality rate for delirium tremens is under 3%. (16) In practice, patients who are attempting to stop drinking alcohol need close personal support and communication, and a reassuring environment, as well as regular monitoring for early signs of a withdrawal syndrome; the latter may require benzodiazepine therapy.