Home > Publications

Comorbidity of mental disorders and substance use: a brief guide for the primary care clinician

11.5 Major clinical issues with gambling and opioid use

Table of contents

Heroin use is relatively rare among people with problem gambling. The use of prescription opioids is more common.
However, problem gambling is prevalent among people on methadone maintenance.
Buprenorphine impairs decision-making less than methadone maintenance in opioid dependent individuals and may therefore be more beneficial when used to manage people with opioid dependence and problem gambling.

11.5.1 Effects of opioids on problem gambling

Heroin use is relatively rare among people with problem gambling(464). The use of prescription opioids is more common^{(432, 464).}
However, amongst people on methadone maintenance:
- Problem gambling is prevalent^{(495, 496)}.
- People with problem gambling are more likely to use other substances when compared with people whose gambling is non-problematic⁽⁴⁹⁵⁾.
- Problem gambling negatively impacts program retention rates⁽⁴⁹⁵⁾.
- People with problem gambling report poorer mental health status than people whose gambling is not problematic⁽⁴⁹⁶⁾.

Opioids can exacerbate the sedative effects of tricyclic antidepressants and mood stabilisers (lithium and sodium valproate). This increases the risk of impaired driving and injury as well as overdose^x.
Fluvoxamine^xxx, fluoxetine^xx, norfluoxetine^xx and paroxetine^x can inhibit buprenorphine and methadone metabolism through inhibition of the CYPs involved in their metabolism^(148-150). This can result in an increase in plasma opioid pharmacotherapy concentrations and potential overdose. This can be a particular issue during induction onto methadone; however, the risk may persist even after stabilisation has occurred^xxx(151-155).
Fluvoxamine is the most potent inhibitor of methadone and buprenorphine metabolism and is the most clinically relevant, therefore, it should be avoided^xxx(150).
Fluoxetine and paroxetine should also be avoided^xx.
Citalopram and sertraline are the least likely SSRIs to have cytochrome mediated drug interactions. However, due to the theoretical potential for an interaction, caution should still be used and individuals monitored closely^x(156).

As naltrexone has been shown to improve problem gambling****^(454-456) and be effective in the management of opioid dependence***⁽⁴⁹⁷⁾, it may be useful in the treatment of comorbid problem gambling and opioid dependence. However, there have been no studies to confirm this and compliance is likely to be an issue.
Buprenorphine improves decision making compared to methadone maintenance in opioid dependent individuals**⁽⁴⁹⁸⁾and may therefore be more beneficial when used to manage people with opioid dependence and problem gambling.