69 - References

References

560 The Maudsley® Prescribing Guidelines in Psychiatry CHAPTER 4 Gambling disorder At the time of writing, no medicines are licensed for the treatment of problem ­gambling. However, international guidelines and draft NICE guidance recommend naltrexone ­off-­label to reduce gambling severity in people with gambling problems.1,2 A 2017 meta-­analysis demonstrated that when people receiving psychological therapy for problem gambling were given naltrexone there was a greater reduction in gambling than with those given placebo.3 Naltrexone is the only drug with likely effectiveness in problem gambling. Other drugs that have been evaluated include nalmefene, serotonin reuptake inhibitors, glutamatergic agents (e.g. N-­acetylcysteine, acamprosate, ­memantine), mood stabilisers (e.g. topiramate, carbamazepine, lithium) and modafinil, olanzapine, ­haloperidol, tolcapone and bupropion.4 Naltrexone should only be initiated in specialist gambling clinics following a discussion of efficacy and adverse effects. Patients should be told about the interaction with concomitant opioids. Following baseline biochemistry analysis to exclude severe renal or hepatic impairment, naltrexone should be initiated at a dose of 25mg, increasing to 50mg with a review of efficacy at 4–6 weeks. Prescriptions could then be transferred to primary care with continuation for as long as the person continues to report benefit, alongside 6-­monthly monitoring of renal and liver function. Clinicians should be aware of the known risks of developing or worsening of impulse control disorders with dopaminergic agents and aripiprazole (and probably other dopamine partial agonists),5–7 particularly in individuals at increased risk for problem gambling.8 References

1. National Institute for Health and Care Excellence. Harmful gambling: identification, assessment and management. In development [GID-­NG10210]. https://www.nice.org.uk/guidance/indevelopment/gid-­ng10210.
2. Thomas SA, et al. Australian guideline for treatment of problem gambling: an abridged outline. Med J Aust 2011; 195:664–665.
3. Mouaffak F, et al. Naltrexone in the treatment of broadly defined behavioral addictions: a review and meta-­analysis of randomized controlled trials. Eur Addict Res 2017; 23:204–210.
4. Mestre-­Bach G, et  al. Pharmacological management of gambling disorder: an update of the literature. Expert Rev Neurother 2024; 24:391–407.
5. Akbari M, et al. Aripiprazole and its adverse effects in the form of impulsive-­compulsive behaviors: a systematic review of case reports. Psychopharmacology (Berl) 2024; 241:209–223.
6. Wolfschlag M, et al. Drug-­induced gambling disorder: epidemiology, neurobiology, and management. Pharmaceut Med 2023; 37:37–52.
7. Williams BD, et al. Aripiprazole and other third-­generation antipsychotics as a risk factor for impulse control disorders: a systematic review and meta-­analysis. J Clin Psychopharmacol 2024; 44:39–48.
8. Medicines and Healthcare products Regulatory Agency. Aripiprazole (Abilify): reminder on known risk of gambling disorder. 2023; https://www.gov.uk/government/news/aripiprazole-­abilify-­reminder-­on-­known-­risk-­of-­gambling-­disorder.