Anxiolytics Health Article

Recommended dosage

The usual adult dosage of diazepam is 2–10 mg taken by mouth two to four times a day. In addition to oral tablets, diazepam is also available as an oral liquid or as an injection that can be given either intramuscularly or intravenously to individuals with severe anxiety symptoms.

Dosages for anxiolytics that are chemically related to diazepam vary. Examples include alprazolam given by mouth in dosages of 0.25–0.5 mg three times a day, or lorazepam taken by mouth in dosages of 0.5–2 mg two or three times a day.

The anxiolytic effects of diazepam occur in as little as 15 minutes, but only last for two or three hours. These features make diazepam an ideal drug for quickly eliminating acute anxiety attacks. On the other hand, lorazepam's anxiolytic effects are a little slower in onset but tend to persist for more than six hours. As a result, lorazepam may be better suited to prevent anxiety in people with generalized anxiety disorder.

Elderly patients may be more sensitive to the side effects of diazepam and related anxiolytics than younger adults. As a result, initial doses are usually reduced and increased slowly in the elderly to avoid excessive sedation and other unwanted side effects.

Precautions

Paradoxically, excitement, rage, anger, or hostility may occur in individuals taking anxiolytics for their calming effects. These reactions may occur secondarily to the relief of anxiety and usually occur within the first two weeks of therapy. If these reactions occur, anxiolytic therapy should be stopped.

Because suicidal tendencies may be present in patients who also have accompanying depressive disorders, only small amounts of anxiolytic agents should be dispensed at any given time to minimize the likelihood of intentional drug overdoses.

Side effects

Diazepam and related anxiolytics are often associated with drowsiness, sedation, confusion, and difficulty maintaining balance. These effects are more pronounced at the beginning of therapy and after dosage increases. People should avoid driving or performing tasks that require alertness until they know how the drugs will affect them.

When using anxiolytics like diazepam, fainting or dizziness sometimes occurs when a person stands up suddenly. Blurred vision may also occur.

When anxiolytics are used in high doses or taken with other drugs that depress the actions of the brain, such as alcohol or barbiturates, the normal breathing responses of the body may be interrupted and patients may stop breathing. For this reason, alcohol and other CNS depressants should be avoided in people taking diazepam and related anxiolytics. It is also best to avoid anxiolytics in those persons with a prior history of drug abuse or those who are suicidal.

Withdrawal symptoms will occur if patients stop taking anxiolytics suddenly. Patients should only discontinue using diazepam and related anxiolytics at the advice of their physician and the dosage of the drugs should be reduced slowly to avoid withdrawal effects.

Interactions

Diazepam will increase the drowsiness or sedative effects of other central nervous system depressants like alcohol or barbiturates. These combinations should be avoided.

Certain drugs, especially those eliminated by the liver, may interfere with the elimination of diazepam from the body. Anticonvulsants, antidepressants, numerous antibiotics, and cimetidine inhibit the elimination of most anxiolytics from the body, causing higher blood levels and increased side effects.

BOOKS

Drug Facts and Comparisons, 6th edition. St. Louis, MO: A Wolter Kluwer Company, 2002.

Kirkwood, Cynthia A. Anxiety Disorders. Pharmacotherapy: A Pathophysiologic Approach, edited by Joseph T. Dipiro, et al. Stamford, CT: Appleton and Lange, 1999.

Mosby's Medical Drug Reference. St. Louis, MO: Mosby, 1999.

Kelly Karpa, PhD, RPh