What is disulfiram?

What is Disulfiram?

Disulfiram is an FDA-approved medication used as an aid in the management of chronic alcohol use disorder by producing an extremely unpleasant reaction when alcohol is consumed, thereby enforcing sobriety through aversive conditioning. 1

Mechanism of Action

Disulfiram works by irreversibly inhibiting aldehyde dehydrogenase (ALDH), the enzyme responsible for metabolizing acetaldehyde during alcohol breakdown. 2, 3

• When a patient taking disulfiram consumes alcohol, acetaldehyde accumulates to levels 5-10 times higher than normal, producing a complex of highly unpleasant symptoms known as the disulfiram-alcohol reaction. 1
• This reaction is proportional to the dosage of both disulfiram and alcohol and persists as long as alcohol is being metabolized. 1
• The inhibition is irreversible in vivo, meaning the reaction can occur up to 1-2 weeks after the last dose of disulfiram. 1, 2
• The active metabolite methyl diethylthiocarbamoyl-sulfoxide (MeDTC-SO) forms a covalent carbamoyl adduct with the ALDH enzyme, resulting in complete cessation of enzyme activity. 3

Clinical Indications and Limitations

Disulfiram is not a cure for alcoholism and is unlikely to have any substantive effect when used alone without proper motivation and supportive psychotherapy. 1

• It is indicated only for selected chronic alcohol patients who are motivated to remain in a state of enforced sobriety so that supportive and psychotherapeutic treatment may be applied. 1
• Current treatment guidelines recommend disulfiram as a second-line treatment option due to safety concerns and lack of high-quality comparative studies. 4
• A systematic review concluded there is little evidence that disulfiram enhances abstinence, and its use has been largely supplanted by newer agents due to poor tolerability. 5
• A 2020 network meta-analysis found limited evidence to support disulfiram's effect on abstinence, noting particular challenges in placebo-controlled trials because patients can easily determine if they are taking the medication. 5

Formulation and Dosing

Disulfiram is available as oral tablets containing 250 mg or 500 mg of the active ingredient. 1

• The chemical name is bis(diethylthiocarbamoyl) disulfide, with molecular formula C₁₀H₂₀N₂S₄. 1
• It appears as a white to off-white, odorless powder that is minimally soluble in water. 1

Critical Safety Considerations and Contraindications

Hepatotoxicity Risk

Disulfiram should be avoided in patients with severe alcoholic liver disease due to potential hepatotoxicity. 5, 6, 7, 8

• The American Association for the Study of Liver Diseases explicitly states disulfiram is not recommended for use in patients with alcoholic liver disease. 8
• The European Association for the Study of the Liver guidelines contraindicate disulfiram in patients with hepatic insufficiency and alcoholic cirrhosis. 8
• Hepatotoxicity is an idiosyncratic reaction that can occur at any time during therapy and requires monitoring, particularly in females and adults over 40 years. 8

Preferred Alternatives in Liver Disease

For patients with alcoholic liver disease or cirrhosis, safer alternatives include:

• Acamprosate: Has no hepatic metabolism and zero hepatotoxicity risk, making it safe across all stages of liver disease. 6, 7, 8
• Baclofen: The only medication with proven safety and efficacy in randomized controlled trials specifically enrolling patients with compensated and decompensated cirrhosis. 7, 8

Patient Selection Criteria

Disulfiram may be useful only for a highly selected group of patients with: 4

• No medical or psychiatric contraindications
• High motivation for complete abstinence
• Adequate family support and supervision
• No hepatic dysfunction or elevated liver enzymes

Many patients with alcohol use disorder fall outside these narrow selection criteria due to high rates of medical and psychiatric multimorbidity and social vulnerability. 4

Emerging Research Applications

Beyond alcohol use disorder, disulfiram is being investigated for:

• Antiviral activity: Broad-spectrum inhibitory effects against SARS-CoV-2, HCV, influenza, HIV, and KSHV through inhibition of viral protein catalytic activity and ejection of Zn²⁺ from viral proteins. 9
• Cancer therapy: Potential anticancer effects, particularly when combined with copper (DSF/Cu), by inducing oxidative stress, inhibiting proteasome activity, and targeting cancer stem cells. 10, 11
• Cocaine use disorder: Mixed results, with some evidence suggesting doses of 250-375 mg/day may prevent increases in cocaine use among methadone-stabilized patients, though efficacy remains limited. 12