It is important for AOD workers to be aware of the complex and dynamic relationship between AOD use, mental health disorders, and prescribed psychiatric medication. During the assessment phase, workers should explore the influence of medication on AOD use and vice versa, as well as the influence of AOD use on mental health symptoms. This clarification will contribute to a comprehensive management and treatment plan, with appropriate goals [276].
AOD workers should also be aware of the potential interactions between AOD use and prescribed medications. Table 29 provides some of the interactions between AOD and prescription medication, but this list is not exhaustive. AOD workers should also note that polydrug use is common among AOD clients, and it may be difficult to clarify potential drug interactions [429]. Similarly, many drugs are composed of many substances (e.g., amphetamines), which makes the potential for interaction difficult to assess [277].
Although Table 29 does not provide a comprehensive list of potential AOD and medication interactions, AOD workers need to be aware of the ways in which AOD use and prescribed medication can affect each other. For example, the selective serotonin reuptake inhibitors (SSRIs) fluoxetine and fluvoxamine have been shown to affect the metabolism of methadone and buprenorphine, with the discontinuation of fluvoxamine associated with opiate withdrawal [430]. In cases where this is unexpected, it is possible that the client may engage in other AOD use (or decrease treatment compliance) to cope with withdrawal symptoms, highlighting the need for worker awareness of the potential for such interactions. Similarly, central nervous system depressants not only increase the potential for overdose and respiratory depression when taken with each other (e.g., benzodiazepines, alcohol, opiates), but also increase the risk of overdose when taken with medication [429].
Table 29: Drug and medication interactions
| Drug type |
Potential medication interaction |
Implications |
| Depressants |
Central nervous system depressants
- Alcohol
- Benzodiazepines
- Opiates
- Antipsychotics
|
TCAs
MAOIs
SSRIs
|
The likelihood of overdose is significantly increased. The sedative effects of benzodiazepines are increased with concurrent use of alcohol. Possibility of reduced effects of prescribed medications. |
| Alcohol intoxication or withdrawal |
Lithium carbonate |
Potential for electrolyte imbalances. Potential for lithium toxicity for those with bipolar disorder. |
| Benzodiazepine or alcohol withdrawal |
Antipsychotics
Antidepressants
|
Lowered seizure threshold with increased potential for seizures. |
| Drug type |
Potential medication interaction |
Implications |
| Stimulants |
| Stimulants (e.g., amphetamines, tobacco, caffeine, cocaine, ecstasy) |
MAOIs
|
Can lead to hypertension (high blood pressure) crisis. |
| Stimulants |
Antidepressants |
Effects can be inhibited. |
| Ecstasy |
Antidepressants |
Linked to high levels of serotonin, associated with hallucinations, mania, hypertension, nausea, muscle rigidity, tremor (serotonin syndrome). |
| Drug type |
Potential medication interaction |
Implications |
| Cannabinoids |
| Cannabinoids |
Antipsychotics |
Increases intensity and frequency of psychosis. |
| Cannabis |
TCAs
Benzodiazepines
|
Increases the sedative effects. |
| Cannabis |
Newer (atypical) antidepressants |
Can cause symptoms of mania, confusion, and psychosis. |
TCAs = tricyclic antidepressants; MAOIs = monoamine oxidase inhibitors; SSRIs = selective serotonin reuptake inhibitors. Adapted from NSW Department of Health [277].
As such, when managing and treating clients with comorbid AOD and mental health conditions, AOD workers need to take into account the level and type of AOD used (especially alcohol), as these may [431]:
- Alter the metabolism of prescribed medication.
- Decrease the effectiveness and/or increase the potential for side effects.
- Warn the client about potential interactions between substances of misuse and prescribed medication.
- Discuss the problems and potential dangers of using non-prescribed AOD to counteract the effects or side effects of prescribed medication.