Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
DISULFIRAM vs ACEPHEN
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Disulfiram irreversibly inhibits aldehyde dehydrogenase, causing accumulation of acetaldehyde after alcohol ingestion, leading to aversive effects such as flushing, nausea, and hypotension.
ACEPHEN (acetaminophen) is a para-aminophenol derivative with analgesic and antipyretic activity. Its mechanism involves inhibition of cyclooxygenase (COX) enzymes in the central nervous system, particularly COX-2, reducing prostaglandin synthesis. It has weak peripheral COX inhibition and minimal anti-inflammatory effect.
Alcohol dependence (FDA-approved),Off-label: Cocaine dependence (limited evidence)
Mild to moderate pain,Fever
250 mg orally once daily, increased to 500 mg orally once daily if needed; maintenance dose typically 250 mg per day (range 125-500 mg).
325-650 mg orally every 4-6 hours as needed; maximum 4 g/day.
Approximately 7–10 hours for parent drug; however, the disulfiram-ethanol reaction can persist up to 14 days due to irreversible inhibition of aldehyde dehydrogenase (ALDH) and slow regeneration of the enzyme. The active metabolite, diethyldithiocarbamate, has a half-life of about 15 hours.
Terminal elimination half-life: 1.0-1.5 hours in adults with normal renal function. Prolonged to 2-5 hours in hepatic impairment or elderly; requires dose adjustment in severe hepatic disease.
Disulfiram is rapidly metabolized in the liver to diethyldithiocarbamate, which is further metabolized; it is primarily excreted in urine and feces.
Acetaminophen is primarily metabolized in the liver via glucuronidation (UGT1A1, UGT1A6, UGT1A9) and sulfation (SULT1A1, SULT1A3). A minor fraction is oxidized by cytochrome P450 enzymes (CYP2E1, CYP1A2, CYP3A4) to a reactive toxic metabolite (NAPQI), which is normally detoxified by conjugation with glutathione.
Primarily renal as metabolites; approximately 80% of a dose is excreted in urine as glucuronide conjugates and other metabolites, with less than 20% excreted in feces via bile. A small amount is eliminated unchanged in urine.
Renal: 90-95% as unchanged drug; tubular secretion and glomerular filtration. Biliary/fecal: <5%.
Approximately 96% bound primarily to albumin and also to lipoproteins.
Approximately 10-20% bound to serum albumin; extensive tissue binding.
Approximately 2–4 L/kg, indicating extensive tissue distribution and accumulation, particularly in adipose tissue due to lipophilicity.
Apparent Vd: 0.5-0.7 L/kg (30-40 L in a 70 kg adult). Distributions into CSF and breast milk.
Rapidly and almost completely absorbed after oral administration; absolute bioavailability is approximately 70–90% due to first-pass metabolism in the liver. No parenteral forms are approved; only oral route (tablets) is used clinically.
Oral: 85-90% (first-pass metabolism minimal). Rectal: approximately 70-80% of oral bioavailability.
No dose adjustment required for renal impairment; no specific GFR-based guidelines exist; use with caution in severe renal impairment.
GFR 10-50 m L/min: 650 mg every 6 hours; GFR <10 m L/min: 650 mg every 8 hours.
Contraindicated in severe hepatic impairment (Child-Pugh class C). In mild to moderate impairment (Child-Pugh A or B), no specific dose adjustment, but monitor liver function. Not recommended in active liver disease.
Child-Pugh Class A: no adjustment; Child-Pugh Class B: maximum 2 g/day; Child-Pugh Class C: maximum 1 g/day.
Not recommended for use in patients under 18 years due to lack of established safety and efficacy.
10-15 mg/kg/dose orally every 4-6 hours; maximum 75 mg/kg/day or 4 g/day, whichever is less.
Initiate at lower dose (125 mg/day) due to age-related decreased function; monitor closely for adverse effects.
Start at lowest effective dose (325 mg every 6 hours); avoid exceeding 3 g/day unless closely monitored.
Disulfiram should never be administered to a patient who is in a state of alcohol intoxication or without the patient's full knowledge and consent. The patient must be fully informed of the disulfiram-alcohol reaction.
Acetaminophen has been associated with cases of acute liver failure, at times resulting in liver transplant and death. Most of the cases of liver injury are associated with the use of acetaminophen at doses that exceed 4,000 milligrams per day, and often involve more than one acetaminophen-containing product.
Hepatotoxicity including hepatitis and hepatic failure; peripheral neuropathy; optic neuritis; psychotic reactions; hypersensitivity; risk of severe disulfiram-alcohol reaction if alcohol is consumed.
Risk of severe liver injury with doses >4000 mg/day; use caution with hepatic impairment, chronic alcoholism, malnutrition, or concomitant hepatotoxic drugs; avoid exceeding recommended dose; limit use to 10 days for pain or 3 days for fever unless directed by physician; serious skin reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis) have occurred.
Concurrent use of alcohol or alcohol-containing preparations; metronidazole; paraldehyde; severe myocardial disease; coronary occlusion; psychosis; severe hepatic impairment; hypersensitivity to disulfiram or other thiuram derivatives.
Hypersensitivity to acetaminophen or any component of the formulation; severe hepatic impairment or active liver disease.
Avoid foods and products containing alcohol: sauces (e.g., wine sauces, beer batter), vinegar (especially red/white wine vinegar), marinades, ripe fruits (fermentation can produce trace alcohol), some desserts (e.g., tiramisu, fruitcakes), alcohol-infused chocolates, non-alcoholic beer/wine (may contain up to 0.5% alcohol). Also avoid mouthwashes, breath sprays, and hand sanitizers with ethanol. Some medications like paraldehyde, chloral hydrate, and metronidazole may cross-react. Even alcohol in cooking may not fully evaporate and can trigger a reaction.
Alcohol: increased risk of hepatotoxicity. Avoid concurrent use. Food: no significant interaction, but taking with food may reduce minor gastrointestinal irritation.
Pregnancy Category C. First trimester: Limited human data; animal studies show embryotoxic effects at high doses. Avoid unless benefit outweighs risk. Second and third trimesters: No specific malformation patterns reported; however, theoretical risk of disulfiram-ethanol reaction causing fetal hypoxia due to maternal acetaldehyde accumulation. Use only if essential and with strict alcohol avoidance.
Pregnancy Category C. First trimester: potential risk of neural tube defects and orofacial clefts (limited human data, animal studies show embryotoxicity). Second and third trimesters: NSAID exposure associated with oligohydramnios, premature ductus arteriosus constriction, and fetal renal impairment. Avoid in third trimester.
Excreted into breast milk in small amounts (M/P ratio not established). No adverse effects reported in nursing infants. However, theoretical risk of disulfiram-ethanol reaction if mother consumes alcohol. Recommend caution and discuss with healthcare provider; generally consider compatible with breastfeeding if mother abstains from alcohol.
Excreted into breast milk in low concentrations (M/P ratio approximately 0.10). Considered compatible with breastfeeding; however, use lowest effective dose for shortest duration given potential for neonatal adverse effects (e.g., thrombocytopenia, renal dysfunction).
No specific dose adjustment recommended in pregnancy. Pharmacokinetic studies in pregnancy not available. Use lowest effective dose (typically 250 mg/day) to minimize risks. Avoid higher loading doses. Discontinue if signs of hepatotoxicity occur.
No standard dose adjustments recommended; however, due to increased plasma volume and metabolism in pregnancy, higher doses may be required to achieve therapeutic effect. Avoid near term.
Disulfiram irreversibly inhibits aldehyde dehydrogenase, causing accumulation of acetaldehyde after alcohol ingestion, leading to severe nausea, vomiting, hypotension, and flushing. Avoid use in patients with severe heart disease, psychosis, or cirrhosis. Monitor LFTs and CBC at baseline and periodically. Disulfiram may also inhibit CYP450 enzymes (CYP2E1, CYP1A2, CYP3A4), potentiating warfarin, phenytoin, and theophylline. Onset of aversion therapy requires 12-48 hours after the last alcohol dose; maintain alcohol-free period of 24 hours before starting. Duration of action persists up to 14 days after discontinuation. Inadvertent alcohol exposure in topical products (mouthwash, colognes) can trigger reactions.
ACEPHEN (acetaminophen) is commonly used for mild to moderate pain and fever. Avoid exceeding 4 g/day in adults to prevent hepatotoxicity. In patients with hepatic impairment, reduce maximum daily dose to 2 g. Consider acetylcysteine for overdose. Onset of action is 15-30 minutes orally.
Avoid all forms of alcohol, including beverages, mouthwash, cough syrup, cooking wine, vinegar, aftershave, and hand sanitizers.,Reaction to alcohol includes severe flushing, nausea, vomiting, chest pain, difficulty breathing, and blurred vision; seek emergency care if symptoms occur.,The disulfiram-alcohol reaction can be fatal even with small amounts of alcohol.,Inform all healthcare providers (including dentists) that you are taking disulfiram.,Reactions may occur up to 14 days after stopping the medication.,Do not take disulfiram if you have recently consumed alcohol; wait at least 12 hours after the last drink.,Carry a medical alert card or wear a bracelet stating you are on disulfiram.,Report any signs of liver toxicity: yellowing of eyes/skin, dark urine, severe fatigue.
Do not exceed 4000 mg (4 grams) in 24 hours.,Avoid drinking alcohol while taking this medication.,Do not combine with other products containing acetaminophen.,Take with food if stomach upset occurs.,Seek immediate medical help if you experience symptoms of liver damage: yellowing of skin/eyes, dark urine, severe abdominal pain.
"Rifapentine, a potent inducer of cytochrome P450 enzymes, significantly increases the metabolism of disulfiram by inducing hepatic CYP3A4 and other metabolic pathways. This induction reduces disulfiram plasma concentrations, potentially diminishing its therapeutic efficacy in maintaining alcohol aversion. The interaction may lead to an increased risk of alcohol consumption relapse and associated clinical consequences."
"Disulfiram inhibits aldehyde dehydrogenase, leading to acetaldehyde accumulation, but also inhibits CYP3A4 and other CYP enzymes. Palbociclib is primarily metabolized by CYP3A4 and is a substrate of this enzyme. Coadministration with disulfiram can significantly increase palbociclib serum concentrations, raising the risk of dose-dependent toxicities such as neutropenia, infections, and fatigue."
"Disulfiram irreversibly inhibits aldehyde dehydrogenase and also suppresses the activity of cytochrome P450 (CYP) 2D6 and other CYP enzymes, thereby reducing the hepatic metabolism of venlafaxine. This can lead to increased plasma concentrations of venlafaxine and its active metabolite O-desmethylvenlafaxine, elevating the risk of dose-dependent adverse effects such as hypertension, nausea, dizziness, and serotonin syndrome. Additionally, disulfiram's own metabolism may be affected, potentially increasing the severity of disulfiram-ethanol reactions."
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about DISULFIRAM vs ACEPHEN, answered by our medical review team.
DISULFIRAM is a Aldehyde Dehydrogenase Inhibitor that works by Disulfiram irreversibly inhibits aldehyde dehydrogenase, causing accumulation of acetaldehyde after alcohol ingestion, leading to aversive effects such as flushing, nausea, and hypotension.. ACEPHEN is a Non-Opioid Analgesic that works by ACEPHEN (acetaminophen) is a para-aminophenol derivative with analgesic and antipyretic activity. Its mechanism involves inhibition of cyclooxygenase (COX) enzymes in the central nervous system, particularly COX-2, reducing prostaglandin synthesis. It has weak peripheral COX inhibition and minimal anti-inflammatory effect.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between DISULFIRAM and ACEPHEN depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of DISULFIRAM is: 250 mg orally once daily, increased to 500 mg orally once daily if needed; maintenance dose typically 250 mg per day (range 125-500 mg).. The standard adult dose of ACEPHEN is: 325-650 mg orally every 4-6 hours as needed; maximum 4 g/day.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between DISULFIRAM and ACEPHEN in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. DISULFIRAM is classified as Category C. Pregnancy Category C. First trimester: Limited human data; animal studies show embryotoxic effects at high doses. Avoid unless benefit outweighs risk. Second and third trimesters: . ACEPHEN is classified as Category C. Pregnancy Category C. First trimester: potential risk of neural tube defects and orofacial clefts (limited human data, animal studies show embryotoxicity). Second and third trimest. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.