M05.10.15 Anti-Anxiety Medications

This section provides an overview of commonly used medications for anxiety disorders in adults. Understanding their mechanism of action, efficacy, and side effects is crucial for medical students when selecting appropriate treatment options.

Benzodiazepines

Description: A class of medications used to treat anxiety disorders, sleep disorders, alcohol withdrawal, and seizures.

Mechanism of Action:

• Acts by depressing the central nervous system (CNS) at specific areas like the limbic system, reticular activating system (RAS), and cortex.
• Achieves this effect by binding to GABA-chloride receptors, enhancing the inhibitory effects of GABA, a calming neurotransmitter.

Metabolism:

• Most benzodiazepines undergo hepatic microsomal oxidation for breakdown in the liver.
• Exceptions include lorazepam, oxazepam, and temazepam, which are metabolized through glucuronide conjugation.

Clinical Considerations:

• Efficacy: Effective for short-term relief of anxiety symptoms.
• Side Effects:
  • Sedation – Drowsiness is a common side effect, which can impair coordination and increase the risk of falls, especially in the elderly.
  • Insomnia – Paradoxically, some people experience rebound insomnia after discontinuing benzodiazepines.
  • Addiction – Benzodiazepines have a high potential for dependence and abuse, particularly with long-term use.
  • Cognitive Impairment – Can cause confusion, memory problems, and difficulty concentrating.
  • Disinhibition – May lead to impulsive or reckless behavior.

Points to Remember:

• Due to the risk of dependence and abuse, benzodiazepines are typically reserved for short-term use (weeks) in managing acute anxiety symptoms.
• Use with caution in patients with a history of substance abuse or dependence.
• Close monitoring is necessary during treatment to assess for potential side effects and dependence.

Buspirone

Description: A medication used for generalized anxiety disorder and other anxiety disorders, particularly when benzodiazepines are not preferred due to concerns about abuse or dependence.

Mechanism of Action:

• Works on the serotonin system, a different neurotransmitter system compared to benzodiazepines.
• The exact mechanism is not fully understood, but it is thought to increase serotonin activity in a way that reduces anxiety.

Clinical Considerations:

• Efficacy: Takes longer to achieve its full effect, typically requiring more than a week of consistent use.
• Side Effects:
  • Sedation – May cause some drowsiness, but generally less pronounced compared to benzodiazepines.
  • Dizziness – Headache, dizziness, and lightheadedness are reported in some users.
  • Nausea – Upset stomach and nausea can occur, especially when taken on an empty stomach.
• Advantages:
  • Less risk of abuse or dependence compared to benzodiazepines.
  • Not potentiated by alcohol.

Points to Remember:

• Buspirone is a good alternative for patients with a history of substance abuse or those concerned about dependence on benzodiazepines.
• Due to the slower onset of action, it may not be suitable for patients needing immediate relief of anxiety symptoms.

Bibliography

• American Psychiatric Association. (2022). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA: Author.
• National Institutes of Health. (2020, November 02). Benzodiazepines. Retrieved from https://www.dea.gov/factsheets/benzodiazepines
• UpToDate. (n.d.). Clinical manifestations and diagnosis of anxiety disorders in adults. Retrieved June 19, 2024, from https://www.uptodate.com/contents/generalized-anxiety-disorder-in-adults-management