Off-label medications for addictive disorders
Off-label agents may help treat certain substance use disorders and gambling.
Naltrexone typically is started at 25 mg/d to assess tolerability and quickly titrated to 50 mg/d. When titrating, common adverse effects include nausea, vomiting, and transient elevations in transaminases. Another opioid antagonist, nalmefene, has also been studied in patients with GD. An RCT by Grant et al29 that evaluated 207 patients found that compared with placebo, nalmefene 25 mg/d for 16 weeks was associated with a significant reduction in gambling assessment scores. In Europe, nalmefene is approved for treating AUD but the oral formulation is not currently available in the US.
N-acetylcysteine is thought to potentially reverse neuronal dysfunction seen in addictive disorders by glutamatergic modulation.30 Research investigating NAC for GD is scarce. A pilot study found 16 of 27 patients with GD reduced gambling behavior with a mean dose of 1,476.9 mg/d.31 An additional study investigating the addition of NAC to behavioral therapy in nicotine-dependent individuals with pathologic gambling found a reduction in problem gambling after 18 weeks (6 weeks + 3 months follow-up).32 Common but mild adverse effects associated with NAC are nausea, vomiting, and diarrhea.
A meta-analysis by Goslar et al33 that reviewed 34 studies (1,340 participants) found pharmacologic treatments were associated with large and medium pre-post reductions in global severity, frequency, and financial loss in patients with GD. RCTs studying opioid antagonists and mood stabilizers (combined with a cognitive intervention) as well as lithium for patients with comorbid bipolar disorder and GD demonstrated promising results.33
Stimulant use disorder
There are no FDA-approved medications for stimulant use disorder. Multiple off-label options have been studied for the treatment of methamphetamine abuse and cocaine abuse.
Methamphetamine use has been expanding over the past decade with a 3.6-fold increase in positive methamphetamine screens in overdose deaths from 2011 to 2016.34 Pharmacologic options studied for OLP of methamphetamine use disorder include mirtazapine, bupropion, naltrexone, and topiramate.
Continue to: Mirtazapine