Comorbidity of mental disorders and substance use: a brief guide for the primary care clinician
6.7 Major clinical issues with anxiety disorders and benzodiazepine use
Table of contents
- Acknowledgments
- Abbreviations
- Preface
- Introduction
1. Levels of evidence- 2. Management of people with comorbidity of mental disorders and substance use
- 3. The common drug groups
- 4. Tobacco
- 5. Depression and substance use
6. Anxiety disorders and substance use- 6.1 Anxiety
- 6.2 Comorbidity with anxiety disorders
- 6.3 Major clinical issues with anxiety disorders and cannabis/ hallucinogen use
- 6.4 Major clinical issues with anxiety disorders and alcohol use
- 6.5 Major clinical issues with anxiety disorders and opioid use
- 6.6 Major clinical issues with anxiety disorders and stimulant (including methamphetamine) use
- 6.7 Major clinical issues with anxiety disorders and benzodiazepine use
- 6.8 Major clinical issues with anxiety disorders and inhalent/ solvent use
- 7. Psychosis (schizophrenia and bipolar disorder) and substance use
- 8. Personality disorders and substance use
- 9. Eating disorders and substance use
- 10. Somatoform disorders and substance use
- 11. Gambling and substance use
- 12. Brain injury, mental disorders and substance use
- 13. Bibliography
- 14. Appendices
- Tolerance to the sedative effects of benzodiazepines and dependence develops within a short period of time.
- It would appear that tolerance to the anxiolytic effects of benzodiazepines does not develop.
- Graded exposure is a highly effective component in the treatment of anxiety disorders. Patients taking benzodiazepines are unable to benefit from this approach if taking doses greater than 10mg diazepam equivalence and doses below this level may interfere with the person's ability to habituate.
- Benzodiazepine use should be discouraged and reduced, with cessation being a long-term goal, and alternative management strategies introduced.
- CBT is effective in reducing symptoms of anxiety and will be more effective if there is minimal sedation and anxiolysis due to benzodiazepine use.
6.7.1 Effects of benzodiazepines on anxiety disorders
- Due to their anxiolytic effects, benzodiazepines are one of the most commonly prescribed forms of pharmacotherapy in the treatment of anxiety symptoms(57, 58). They are not, however, the recommended first-line treatment for anxiety disorders.
- Tolerance to the sedative effects of benzodiazepines and dependence develops within a short period of time.
- It would appear that tolerance to the anxiolytic effects of benzodiazepines does not develop(196).
- If short-acting benzodiazepines are used (e.g. alprazolam, oxazepam, temazepam), rapidly fluctuating drug plasma concentrations may exacerbate the symptoms of the anxiety disorder.
- Patients prescribed benzodiazepines for anxiety disorders may be less responsive to and less willing to accept psychological therapies than those who are not.
6.7.2 Interactions between benzodiazepines and therapeutic agents for anxiety disorders
- There is an increased risk of sedation and overdose with the combination of benzodiazepines and sedative antidepressants such as tricyclics and mirtazepinex.
- Benzodiazepines and antidepressants are both metabolised by CYP 450 enzymes which may result in the inhibition or induction of either drug group. Therefore, individuals should be monitored closely to ensure they are experiencing the appropriate therapeutic effectx.
- Fluvoxamine will inhibit the metabolism of alprazolam, midazolam, triazolam and diazepam, causing increased plasma concentrations, sedation and potential toxicityx.
- Citalopram and sertraline are the least likely SSRIs to have cytochrome mediated drug interactionsx.
6.7.3 Management approaches to comorbid anxiety disorders and benzodiazepine use
- Graded exposure is a highly effective component in the treatment of anxiety disorders. Patients taking benzodiazepines are unable to benefit from this approach if taking doses greater than 10mg diazepam equivalence and doses below this level may interfere with the person's ability to habituate to anxiety triggers.
- Benzodiazepine use should be discouraged and reduced, with cessation being a long-term goal and alternative management strategies introduced.
- If large quantities of benzodiazepines (e.g. 40mg diazepam daily equivalent or more) are being consumed then inpatient withdrawal to lower levels should be considered to avoid and manage seizure risk(194).
- If dependence has developed then graduated withdrawal through slow reduction of dosage should be commenced****(194-196), possibly after transferring the patient onto a long acting benzodiazepine.
- Lower levels of baseline anxiety at the time of benzodiazepine withdrawal are the best predictor of successful taper(196).
- If long-term benzodiazepine use is indicated, then:
- This should be subject to a contract with the patient.
- Authorities should be advised, including registration with the relevant local government health authority.
- The seeking of additional benzodiazepines from other prescribers should be monitored (e.g. using the Authority to release personal PBS claims information to a third party form).
- Daily or weekly dispensing of benzodiazepines should be considered and may assist with controlling use.
- CBT is effective in reducing symptoms of anxiety****(202) and will be more effective if there is minimal sedation and anxiolysis due to benzodiazepine use(196).
- CBT has been shown to improve the likelihood of patients successfully tapering and ceasing benzodiazepines when they also have an anxiety disorder***(203, 204).
- Antidepressant medication (SSRIs or other non-sedating antidepressants) can be commenced with the patient still taking benzodiazepines.
- Citalopram and sertraline are the least likely SSRIs to have cytochrome mediated drug interactions.
