Anxiety disorders are among the most common emotional problems seen by a physician or mental health professional. Anxiety is a component of virtually all psychiatric presentations. Anxiety disorder as a primary diagnosis constitutes approximately 10 to 20 percent of primary psychiatric diagnoses in an outpatient practice setting. Antianxiety medications are known as minor tranquilizers; they are also called sedatives because of their sedating effects. The treatment of anxiety typically uses a variety of antianxiety medications, the most common group of which is the benzodiazepines, which have sedative action. Among benzodiazepines, the most widely used as primary antianxiety medications are alprazolam (Xanax), diazepam (Valium), chlordiazepoxide (Librium), lorazepam (Ativan), oxazepam (Serax), and clonazepam (Klonopin). Benzodiazepines are relatively safe in overdose. Other antianxiety medications such as phenobarbi-tal, meprobamate, and various barbiturates have fallen out of favor in modern clinical practice; hence, if an antianxiety medication is necessary, benzodiazepines are the medications of choice. Choosing a benzodiazepine among the many that are available depends on various factors, including pharmacological characteristics such as half-life, method of metabolism, onset of action, duration of action, and purpose. These and other factors will be explained further.