Effective Use

The Efficacy of Benzodiazepines and Z-drugs

In general, it has been shown that benzodiazepines work quite well in the short-term for several common uses, including in the treatment of anxiety and insomnia. However, when a benzodiazepine is used long-term, not only does it lose its efficacy, but there is a significant risk of physiological dependence as well as the development of side effects.  No well-accepted line has been drawn between “short-term” and “long-term” use, although most benzodiazepine prescription guidelines list long-term benzodiazepine use as anything over 4 weeks’ consecutive use, which is how the term is used in this website. If you read the Dependence page, it becomes clear that the effects of “long-term” use can often be seen after as little as 2 weeks of use.

Since the introduction of chlordiazepoxide (Librium®) in 1960, various benzodiazepines have been approved by the FDA to treat anxiety, panic disorder, muscle spasms and alcohol withdrawal. In 1981, temazepam (Restoril®) was introduced as the first benzodiazepine that is FDA-approved to treat insomnia. The insomnia-targeted Z-drugs made their debut in 1988 with zopiclone, which is no longer approved for sale in the United States.  Please refer to the table called “Comparison of Benzodiazepine Pharmacology” for a list of all the benzodiazepines and Z-drugs currently available in the United States. For studies and reviews on each of the specific benzodiazepines and Z-drugs please refer to listings within the Benzodiazepine Reference Library.

Since those first introductions, benzodiazepines and Z-drugs have been prescribed for a vast range of medical disorders, many of which are listed on the Prescriber page. Many prescribers consider them to be essential tools, although the World Health Organization has declared that benzodiazepines are “essential medicines” for very few applications. It lists only diazepam, midazolam and lorazepam as anti-convulsants, and diazepam for palliative care and to treat anxiety disorders.