Benzodiazepine

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Other medications used in the treatment of anxiety disorders include selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants (TCAs), monoamine oxidase inhibitors (MAOIs), other agents (e.g., barbiturates, meprobamate, sedative-hypnticcs, antihistamines, and buspirone), and combination treatments (Patterson, 2006; Preston, O’Neal, & Talaga, 2008).

Humans (and other animals) have adaptive survival mechanisms that casue them to experience fear, which can help them avoid harmful situations. For example, when confronted with a threat (e.g., coming across a rattlesnake), the body may react with increased heart rate, sweating, and other fight-or-flight responses. This adrenaline response may increase one’s ability to escape a dangerous situation.

The ability to learn what situations may be dangerous allows individual to avoid these situations in the future. However, when fear is out of proportion to actual threat (e.g., reacting with fear to any mention of snakes), anxiety may ensue. Avoidance learning consists of conditioned fear (an immediate response (i.e., movement, such as running away), which involves other brain structures, including the basal ganglia, frontal cortex, and hippocampus (LeDoux, 1996). Benzodiazepines enhance the effects of the neurotransmitter gamma-aminobutyric acid (GABA), an inhibitory chemical messenger that helps regulate excitability, ameliorating the conditioned fear response (LeDoux, 1996).

The first benzodiazepine—chlordiazepoxide (Librium)—was developed in 1957. Benzodiazepines were a significant improvement over previous anxiety medications, which included barbiturates, meprobamate (Miltown), tybamate, glutethimide (Doriden), methyprylon (Noludar), and ethchlorvynol (Placidyl; Preston et al., 2008). Many of these earlier tranquilizers have high abuse potential; they can cause tolerance and severe withdrawal symptoms.

Because many people have anxiety or insomnia, benzodiazepines have been widely used. Valium, which was introduced in 1963, became one of the best-selling pharmaceutical drugs on the market, reaching peak sales in the United in 1978 (Bakalar, 2005). Valium had a mixed reputation: at times it was promoted as a harmless panacea. It gained cultural notoriety in the Rolling Stones song “Mother’s Little Helper.” Some of the dangers of Valium (e.g., addiction and withdrawal) were described in 1979 book I’m Dancing as Fast as I can (Gordon, 1979).

Benzodiazepines have both sedative and hypnotic properties. Medications with sedative properties are used to treat anxiety; hypnotics are used in the treatment of insomnia (to induce or maintain sleep). Benzodiazepines are also used as anesthetics or to aid in withdrawal from other drugs.

Benzodiazepines are fast acting and effective against anxiety. They can cause sedation, slurred speech, lack of coordination, and lessening of inhibitions. Some benzodiazepines (triazolam, midazolam, and lorazepam) can cause anterograde amnesia, resulting in memory loss for a period of time after the drug has worn off (Preston et al., 2008).

Different benzodiazepines have varying degrees of abuse potential, physiological dependence, and withdrawal symptoms. It can be dangerous to combine benzodiazepines with alcohol; this combination is what caused Karen Ann Quinlan’s comaOpens in new window (Preston et al., 2008).

In addition to Librium, some of the better known benzodiazepines include alprazolam (Xanax), clonazepam (Klonopin), diazepam (Valium), flunitrazepam (Rohypnol), flurazepam (Dalmane), lorazepam (Ativan), midazolam (Versed), temazepam (Restoril), and triazolam (Halcion).

Some of the newer atypical benzodiazepines (e.g., ProSom, quazepam) and nonbenzodiazepines (e.g., Ambien, Lunesta, Sonata) are used as hypnotics; they may be associated with less cognitive impairment, daytime fatigue, and a reduced risk of dependency. Benzodiazepines should not be used during pregnancy or while nursing (Preston et al., 2008).