Anxiolytics: Therapeutic Monitoring
Benzodiazepines
Benzodiazepine dosing is generally titrated to maximize symptom relief while minimizing side effects and the potential for abuse. No routine monitoring is required; although serum drug levels can be obtained, they are not of great clinical use. Care must be taken in prescribing benzodiazepines because of their ability to cause physiologic dependence. They cannot be discontinued abruptly due to the risk of a withdrawal syndrome that may include seizures.
Buspirone
No routine monitoring or drug levels are required when using buspirone.
Side Effects and Adverse Drug Reactions
Benzodiazepines
The major side effects ofbenzodiazepines are related to the CNS. The primary side effect of benzodiazepines is sleepiness or a general groggy feeling.
Although benzodiazepines are often used to treat agitation, they may produce disinhibition (and therefore worsen agitation) in some patients (i.e., the elderly). Benzodiazepines are minimally depressive to the respiratory system in healthy individuals but can lead to fatal carbon dioxide retention in patients with chronic obstructive pulmonary disease.
In healthy individuals, death after overdose on benzodiazepines alone is rare but does occur when benzodiazepines are taken with alcohol and other CNS depressant medications.
Buspirone
Buspirone does not tend to cause sedation, nor does it produce a significant withdrawal syndrome or dependence. The major side effects are dizziness, nervousness, and nausea.
KEY POINTS
1. Anxiolytics include benzodiazepines and buspirone.
2. Benzodiazepines bind to GABA A receptors and have a comparatively rapid onset of action; buspirone binds to Serotonin receptors and takes effect after weeks of daily usage.
3. Benzodiazepines have a wide variety of uses, including anxiolysis, alcohol detoxification, agitation, and insomnia.
4. Benzodiazepines produce physiologic dependence and may manifest a significant withdrawal syndrome.
5. Buspirone,treats only generalized anxiety, but does not cause physiologic dependence.
Revision date: June 11, 2011
Last revised: by Dave R. Roger, M.D.