Pharmacotherapy for Polysubstance Use Disorder in a 55-Year-Old Patient
For this 55-year-old patient with alcohol dependence, cannabis use disorder, and cocaine abuse, initiate disulfiram 250 mg daily as first-line therapy, as it addresses both alcohol and cocaine use simultaneously, combined with naltrexone 50-100 mg daily for additional alcohol relapse prevention. 1
Alcohol Dependence: Primary Pharmacologic Target
First-Line Medication Strategy
Disulfiram (250 mg/day) should be the cornerstone medication because it uniquely addresses both the alcohol dependence and cocaine abuse in this patient. 1 This dual benefit is critical given the polysubstance presentation. Research demonstrates that disulfiram combined with psychotherapy produces significantly better treatment retention and longer duration of abstinence from both alcohol and cocaine compared to psychotherapy alone. 2
Consider adding naltrexone (100 mg/day) to disulfiram for enhanced alcohol relapse prevention. 1 The combination strategy is specifically recommended by the American Academy of Family Physicians for patients with co-occurring alcohol and cocaine use. 1 Naltrexone at 50 mg daily reduces heavy drinking days and has demonstrated efficacy in older adults (50-70 years), making it appropriate for this 55-year-old patient. 3, 4
Alternative Monotherapy Options
If disulfiram is contraindicated or not tolerated:
Acamprosate 666 mg three times daily (1,998 mg/day total) is highly effective for maintaining abstinence in detoxified patients and has no hepatotoxicity risk, making it safer in patients with potential liver disease. 5, 6, 7
Naltrexone 50 mg daily as monotherapy reduces return to any drinking by 5% and binge-drinking risk by 10%, with proven efficacy in the 50-70 age range. 6, 4
Essential Thiamine Supplementation
All alcohol-dependent patients must receive thiamine 100-300 mg daily orally to prevent Wernicke's encephalopathy. 1, 8 This is non-negotiable and must be administered before any glucose-containing IV fluids if the patient requires acute medical care. 8 Given the patient's age (55 years) and likely chronic alcohol use, assume nutritional deficiency and provide prophylactic thiamine. 5
Cocaine Abuse: Limited Pharmacologic Options
No FDA-approved medications exist for cocaine dependence in primary care settings. 1 However, the disulfiram prescribed for alcohol dependence provides the additional benefit of reducing cocaine use. 1, 2 The mechanism appears related to disulfiram's effect on dopamine metabolism, and clinical trials show cocaine and alcohol use remain strongly correlated throughout treatment, particularly with disulfiram. 2
Psychosocial interventions are the evidence-based standard for cocaine abuse. 1 Specifically, contingency management combined with community reinforcement approach demonstrates the highest efficacy and acceptability for stimulant addiction, superior to cognitive behavioral therapy alone. 5
Cannabis Use Disorder: No Pharmacotherapy Indicated
No specific medications are recommended for cannabis withdrawal or dependence. 5 Cannabis withdrawal is best managed in a supportive environment with symptomatic treatment only (e.g., for agitation or sleep disturbance). 5
Brief psychosocial interventions (5-30 minutes) incorporating motivational principles should be offered for cannabis use disorder. 5 This single-session intervention includes individualized feedback and advice on reducing or stopping cannabis consumption with follow-up offered. 5
Psychosocial Support: Mandatory Adjunct
Medications alone have limited efficacy—concurrent psychosocial support is essential. 1 The evidence base demonstrates that:
Motivational interviewing techniques help reduce alcohol use and prevent cocaine relapses, particularly important given the strong association between alcohol and cocaine use. 9
Cognitive behavioral therapy or motivational enhancement therapy should be integrated with pharmacotherapy for optimal outcomes. 6
Mutual help groups (Alcoholics Anonymous, Narcotics Anonymous) should be strongly encouraged as adjunctive support. 5
Critical Pitfalls to Avoid
Naltrexone-Specific Warnings
Do not initiate naltrexone during active opioid use or before a 7-10 day opioid-free period, as it will precipitate severe withdrawal. 1, 3 Verify the patient has no concurrent opioid use before prescribing.
Avoid naltrexone in patients with significant liver disease due to hepatotoxicity risk. 1, 3 Check baseline liver function tests given the alcohol dependence history.
Disulfiram Precautions
Disulfiram should be avoided in patients with severe alcoholic liver disease due to hepatotoxicity risk. 5 However, it requires reliable adherence and patient selection—the patient must be motivated and understand the severe disulfiram-alcohol reaction. 1
Thiamine Administration Sequence
Never administer glucose before thiamine in at-risk patients, as this can precipitate acute Wernicke's encephalopathy. 1, 8 This is a potentially fatal but preventable complication.
Treatment Setting Considerations
Outpatient management is appropriate if the patient has:
- Mild-to-moderate withdrawal symptoms
- Stable medical and psychiatric status
- Adequate social support
- No history of severe withdrawal complications (seizures, delirium tremens) 6
Inpatient management is required if the patient has:
- Risk of severe alcohol withdrawal
- Concurrent serious psychiatric disorder
- Lack of adequate support or supervision
- Previous treatment failure in outpatient settings 1, 6
Monitoring and Follow-Up
Close monitoring is essential during the initial treatment phase. 5 Watch for:
- Depression or psychosis during withdrawal (can occur with any substance, requiring specialist consultation) 5
- Treatment adherence, particularly with disulfiram which requires daily compliance 1
- Continued substance use via urine toxicology screens 2
- Emergence of withdrawal symptoms requiring dose adjustments
If office-based treatment proves ineffective, specialist referral is indicated. 1 Co-occurring polysubstance use with psychiatric comorbidity represents a common indication for addiction specialist consultation. 1