How is disulfiram used to treat cocaine use disorder, including dosing and contraindications?

Disulfiram for Cocaine Use Disorder

Disulfiram is NOT a first-line treatment for cocaine use disorder and should only be considered as an adjunctive pharmacotherapy in specific clinical contexts, particularly in patients with comorbid opioid dependence on methadone or buprenorphine maintenance, while recognizing that psychosocial interventions remain the evidence-based standard of care.

Current Treatment Standard

The evidence is clear that psychosocial interventions, not pharmacotherapy, are the first-line treatment for cocaine use disorder 1. Specifically, the combination of contingency management plus community reinforcement approach demonstrates the strongest efficacy and acceptability both short-term and long-term 1. There is little evidence supporting pharmacotherapy as primary treatment 1.

Disulfiram's Limited Role

Evidence for Efficacy

The most recent comprehensive evidence from a 2024 Cochrane review 2 shows:

• Disulfiram may increase point abstinence compared to placebo (RR 1.58,95% CI 1.05-2.36), but the certainty of evidence is low
• Disulfiram has little or no effect on:
  • Frequency of cocaine use
  • Amount of cocaine use
  • Continuous abstinence
  • Treatment retention (dropout rates)

Proposed Mechanism

Disulfiram inhibits dopamine β-hydroxylase (DβH), which converts dopamine to norepinephrine 3, 4. This may theoretically blunt cocaine's reinforcing effects by altering catecholamine metabolism. However, clinical translation of this mechanism remains inconsistent.

Dosing Considerations

Standard Dosing (from FDA label) 5:

• Initial phase: 500 mg daily for 1-2 weeks (after 12 hours alcohol abstinence)
• Maintenance: 250 mg daily (range 125-500 mg; maximum 500 mg/day)
• May be taken in morning or at bedtime if sedation occurs

Critical Dosing Caveat

Doses below 250 mg/day may be contraindicated 6. A randomized trial found that 62.5 mg and 125 mg doses actually increased cocaine use over time, while 250 mg showed potential benefit. Additionally, weight-based dosing appears important - disulfiram dose (mg/kg) was negatively correlated with cocaine choices in laboratory studies 7, suggesting fixed dosing may produce unreliable effects.

Pharmacogenetic Considerations

The DBH -1021C/T polymorphism (rs1611115) predicts treatment response 4:

• Patients with normal DβH genotype: Cocaine-positive urines dropped from 84% to 56% on disulfiram (p=0.0001)
• Patients with low DβH genotype: No disulfiram effect observed

This suggests disulfiram efficacy depends on adequate baseline DβH enzyme levels to inhibit. However, routine genotyping is not yet standard practice.

Specific Clinical Context Where Disulfiram May Be Considered

Methadone or buprenorphine-maintained patients with comorbid cocaine dependence represent the population with the most consistent (though still modest) evidence 8, 6, 3:

• One trial showed disulfiram-treated subjects decreased quantity and frequency of cocaine use significantly more than placebo in methadone-maintained patients 3
• Another trial in buprenorphine-treated patients showed reduced frequency of cocaine use, particularly in T-allele carriers of the DBH gene 8

Contraindications 5

Disulfiram is absolutely contraindicated in:

• Recent alcohol, metronidazole, or paraldehyde use
• Severe myocardial disease or coronary occlusion
• Psychoses
• Hypersensitivity to disulfiram or thiuram derivatives

Safety Concerns

Alcohol Interaction Risk

The disulfiram-ethanol reaction (DER) produces hypotension, tachycardia, nausea, and flushing 9. While moderate cocaine use (30 mg IV) did not exacerbate DER-related hypotension in one safety study, the 500 mg/day disulfiram arm was stopped prematurely due to safety concerns 9. This is particularly relevant given that most cocaine users have comorbid alcohol use disorder.

Cardiovascular Effects

Disulfiram enhanced cocaine-induced cardiovascular effects in controlled studies 7, though one study suggested it may have reduced subjective cocaine high 9. Given cocaine's inherent cardiotoxicity, this warrants caution.

Practical Algorithm

IF considering disulfiram for cocaine use disorder:

1. First, implement evidence-based psychosocial interventions (contingency management + community reinforcement approach) 1

2. Only consider disulfiram as adjunctive therapy if:

   • Patient has comorbid opioid dependence on methadone/buprenorphine maintenance
   • Psychosocial interventions alone are insufficient
   • No contraindications exist (especially cardiac disease, active alcohol use)

3. Dosing:

   • Use 250 mg daily (not lower doses)
   • Consider weight-based dosing for more reliable effects
   • Ensure 12+ hours alcohol abstinence before initiation

4. Monitoring:

   • Verify medication adherence (patients may discard tablets)
   • Monitor for alcohol use (high risk population)
   • Assess cardiovascular status regularly

Bottom Line

Disulfiram remains an unproven and potentially risky option for cocaine use disorder with low-certainty evidence showing minimal benefit on most meaningful outcomes 2. Its use should be restricted to adjunctive treatment in methadone/buprenorphine-maintained patients who have failed evidence-based psychosocial interventions, using 250 mg daily dosing with careful monitoring for alcohol use and cardiovascular complications.