Comorbidity of mental disorders and substance use: a brief guide for the primary care clinician
7.7 Major clinical issues with psychosis and benzodiazepine use
- Benzodiazepines may be required for breakthrough anxiety and agitation in psychosis.
- Benzodiazepines should be restricted to short-term use particularly in outpatient settings.
- If dependence has developed, then graduated withdrawal through slow reduction of dosage should be commenced, possibly after transferring the patient onto a long-acting benzodiazepine.
- If long-term benzodiazepine use is indicated, then this should be monitored closely.
7.7.1 Effects of benzodiazepines on psychotic disorders
- Benzodiazepines may be required for breakthrough anxiety and agitation in psychosis(2).
- Benzodiazepine use should be restricted to short-term use particularly in outpatient settings as those with substance-use disorders are at a greater risk of abusing benzodiazepines(2, 196).
- Benzodiazepines may be used by patients to self-manage positive psychotic symptoms.
- Benzodiazepines will enhance the sedative effects of tricyclic antidepressants used to treat associated depression(2) with schizophrenia, which increases the risk of overdose.
- Benzodiazepines may exacerbate negative symptoms such as depression and psychomotor retardation as well as slowing of cognitions.
7.7.2 Interactions between benzodiazepines and therapeutic agents for psychotic disorders
- Benzodiazepines will increase the sedative effects of antipsychoticsx.
- When used with clozapinex, benzodiazepines may induce delirium, severe sedation and respiratory depression.
7.7.3 Management approaches to comorbid psychotic disorders
- Due to their sedative effects, benzodiazepines, in conjunction with major tranquilisers, e.g. lorazepam, clonazepam and diazepam, can be useful for the acute management of psychotic episodes.
- If large quantities of benzodiazepines (e.g. 40mg diazepam daily equivalent) 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.
- 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.


