Benzodiazepines for Anxiety

It is thought that benzodiazepines relieve anxiety by enhancing the effects of the neurotransmitter GABA. The mechanism of action is not fully understood, however.

The side effects of benzodiazepines are generally minor. They include mild disturbances of thinking and, in rare instances, slowed breathing. Two side effects of benzodiazepines, drowsiness and clumsiness, may lead to an increased risk of accidents while driving. A study from Quebec found that users of benzodiazepines had a 26 percent greater chance of being involved in a car crash than nonusers. The increased risk for those using benzodiazepines was highest (45 percent) during the first week of therapy.

The most troublesome issues with benzodiazepine treatment are the development of tolerance (decreased effectiveness of a given dose with continued use) and both physical and psychological dependence, especially with long-term use of a drug at high doses. Physical dependence is defined by the development of a specific set of physical symptoms upon withdrawal of a drug. Psychological dependence refers to a persistent desire for the drug after it has been discontinued.

Tolerance may cause a person to request, and at times receive, increasingly larger doses to maintain benefits. In this instance, the person may be switched to an SSRI or a tricyclic drug instead of higher doses of a benzodiazepine. The risk of side effects, such as drowsiness and confused thinking, rises with increased doses of benzodiazepines.

When a person is physically or psychologically dependent on benzodiazepines, he or she can experience serious symptoms during withdrawal, including irritability, agitation, restlessness, insomnia, loss of appetite, tremor, muscle aches, and, in some people, confusion or seizures. The danger of severe withdrawal symptoms can be diminished by using the smallest effective dose of a benzodiazepine for the shortest possible time and by slowly tapering the drug dose as it is discontinued.

First-Line Medications to Treat Anxiety

Although benzodiazepines are still commonly used to treat anxiety, two classes of antidepressant drugsSSRIs and tricyclics—have become the first line of treatment. The serotonin and norepinephrine reuptake inhibitors and tetracyclics also are used to treat these conditions. These drugs are not habit forming and can be effective in low doses.

Clearly, antidepressants may be indicated when a person with anxiety is also depressed. Tricyclics and SSRIs take several weeks to work, making them slower acting than benzodiazepines, but they do bring a fast-acting benefit to people with anxiety by promoting better sleep, which quickly improves daily functioning.

Updated by Remedy Health Media

Publication Review By: Karen L. Swartz, M.D.

Published: 06 Mar 2011

Last Modified: 07 Oct 2014