Polysubstance use disorder

Background

• Co-occurring substance use disorders are common, involving both legal and illegal substances.
• Alcohol use disorder and Tobacco use disorder are the most common co-occurring substance use disorders, followed by opioid use disorder, cocaine use disorder, and cannabis use disorder.

Risk Factors1

• Younger age
• Lower education
• Lower socioeconomic status
• Childhood abuse
• Male sex

Epidemiology

• About 25% of people with one substance use disorder have co-occurring substance use disorders1.

Management

Screening

• ASSIST, TAPS, and AUDIT-C can all be used

Treatment

• The co-occurring disorders should ideally be treated concurrently, based on the severity of each one.

Benzodiazepine and opioid use disorders

• Benzodiazepine use has a high risk of hepatitis c virus infection, HIV infection, and death.
• Specifically with opioids, it increases the risk of respiratory depression, overdose, and death.
• However, the risk of death from an untreated opioid use disorder is likely higher than if it is treated despite the concurrent use of benzodiazepines.
• Despite this, opioids and benzodiazepines should not be coprescribed unless clearly documented as a taper.

Cocaine and alcohol use disorders

• Old data suggest that as much as 60-80% of patients with cocaine use disorder have a concurrent alcohol use disorder.
• Coingestion causes the formation of a cocaine metabolite cocaethylene, not otherwise present, which increases the effects (positive and negative) of the cocaine and prolongs its half-life.

Opioid and alcohol use disorders

• Continue with standard treatments including motivational interviewing.
• For medical management of the opioid use, Suboxone is likely safer in these patients than methadone.
• For medical management of the alcohol use, naltrexone is contraindicated since it will precipitate withdrawal, but acamprosate and gabapentin can still be used.
  • However, gabapentin should be used with care, since concomitant opioid and gabapentin use may increase fatal overdose compared to those without gabapentin use.

Tobacco use disorder

• Many patients who are being treated for other substance use disorders are interested in smoking cessation as well.
• Patients should be screened and offered treatment for concurrent tobacco use disorder.

Alcohol and tobacco use disorders

• This combination is the most common diagnosis among those with co-occurring substance use disorders.
• Smoking is associated with increased alcohol consumption and severity of alcohol use disorder, as well as the usual ill effects of smoking and alcohol use.
• Combination varenicline and naltrexone appears effective.
• Psychosocial interventions including brief interventions and contingency management may be helpful.

Prognosis

• More severe physical and mental health problems, including liver disease and HIV, compared to those with a single substance use disorder.
• Concurrent use of sedatives, such as opioids with benzodiazepines or alcohol, is associated with higher rates of respiratory depression, overdose, and death.