Sedative, Hypnotic, and anxiolytic substance use disorders

Sedative, hypnotic, and anxiolytic drugs are widely used. They are all cross-tolerant with each other and with alcohol. Included in this class are barbiturates and benzodiazepines. Of these, the benzodiazepines are the most widely prescribed and available.

Epidemiology
Approximately 15% of the general population is prescribed a benzodiazepine in a given year. Some patients abuse these drugs.

Clinical Manifestations


History, Physical and Mental Status
Examinations, and Laboratory Tests

Sedative-hypnotic drug abuse and dependence are associated with syndromes of intoxication, withdrawal, and withdrawal delirium that resemble those of alcohol.

Intoxication only can be distinguished from alcohol intoxication by the presence (or absence) of alcohol on the breath, or in the serum or urine.
Barbiturates, when taken orally, are much more likely than benzodiazepines to cause clinically significant respiratory compromise. Intoxication can be confirmed through quantitative or qualitative serum or urine toxicologic analyses. Serum toxicologic screens can identify the presence of benzodiazepines and barbiturates and their major metabolites.

Withdrawal symptoms are listed in Table 5-1.
Withdrawal delirium (confusion, disorientation, and visual and somatic hallucinations) has an onset of 3 to 4 days after abstinence. Dependence requires the presence of three or more of the seven symptoms listed in Table 5-1.

Management

Treatment of sedative-hypnotic withdrawal may be on an outpatient or inpatient basis. Generally, inpatient detoxification is required when there is comorbid medical or psychiatric illness, prior treatment failures, or lack of support by family or friends. On an inpatient unit, benzodiazepines or barbiturates may be administered and tapered in a controlled manner. Withdrawal from short-acting substances is generally more severe, whereas withdrawal from longer-acting substances is more prolonged.

Withdrawal from barbiturates is more dangerous than from benzodiazepines: it can (much more easily) lead to hyperpyrexia and death. Withdrawal is managed by scheduled dosing and tapering of a benzodiazepine or barbiturate (diazepam or phenobarbital).

In patients who have been abusing alcohol and benzodiazepines or barbiturates, it may be necessary to perform a pentobarbital challenge test. This test allows for the quantification of tolerance to perform a controlled taper, thereby reducing the problems of withdrawal.

Treatment of sedative-hypnotic dependence resembles that for alcohol dependence. After detoxification, the patient can enter a residential rehabilitation program or a day or evening treatment program. Referral to AA is appropriate because the addiction issues and recovery process are similar.
Families may be referred to AI-Anon, an AA focused family education and support group.

KEY POINTS
1. Sedatives and hypnotic drugs are cross-tolerant with alcohol.
2. They have intoxicating effects and result in withdrawal states similar to alcohol.
3. Tolerance can be measured by a pentobarbital challenge test.
4. Treatment resembles that for alcoholism.

Provided by ArmMed Media
Revision date: July 5, 2011
Last revised: by Janet A. Staessen, MD, PhD