Dimercaptopropane Sulfonate (DMPS)
Pronunciation: (yoo-NITH-ee-ol).
- Generic name
- Dimercaptopropane sulfonate (DMPS)
- Brand names
- Unithiol, Chelaton, Dimaval, DMPS
- Drug class
- Chelating Agent
Availability and supply rules vary by country
Trade names by country:
Australia: · Full directory
What Dimercaptopropane sulfonate (DMPS) is and how it works
Uses, formulations, monitoring, and supply rules can differ by patient, product, and country. Follow the exact local product information and professional advice.
Mechanism of action: how Dimercaptopropane sulfonate (DMPS) works
Unithiol (DMPS) is a water-soluble chelating agent containing two sulfhydryl (–SH) groups. It binds to heavy metal ions (such as mercury, arsenic, and lead) via these groups, forming stable, non-toxic, water-soluble complexes that are excreted in the urine. This reduces the bioavailability and toxicity of the metals.
What Dimercaptopropane sulfonate (DMPS) is used for
Mercury poisoning
Mercury poisoning
Arsenic poisoning
Arsenic poisoning
Lead poisoning
Used for lead poisoning in some countries as a clinician-supervised chelation option; succimer (DMSA) or other agents may be preferred depending on local practice.
Before taking Dimercaptopropane sulfonate (DMPS)
Do not take / not appropriate for
- known hypersensitivity to DMPS or other chelating agents, and severe renal impairment due to risk of accumulation and toxicity. (Contraindication)
Tell your clinician about
How to take Dimercaptopropane sulfonate (DMPS)
- General Instructions: Take Unithiol exactly as prescribed by your healthcare provider. Consult your doctor before any change to your dose; your doctor will advise whether the medication should be changed or stopped.. Adult Dosing: In severe acute heavy-metal poisoning, clinicians typically give 250 mg (about 3–5 mg/kg) by slow intravenous injection, repeated at intervals of a few hours according to severity and response. For less severe or chronic poisoning, oral dosing of 100 mg three to four times daily is typical. The treating clinician sets the exact regimen and duration.. Pediatric Dosing: Dosing in children is weight-based and determined by a poisons-centre or treating specialist, with careful monitoring. Dosing frequency and duration depend on the type and severity of poisoning.. Administration: For injections, Unithiol is administered by a healthcare professional. Oral forms should be taken with water, with or without food, as directed.. When To Seek Review: Continue taking Unithiol for the full course prescribed, even if you feel better. Your doctor will determine when treatment should end; continue as directed until they advise otherwise.. Storage: Store at room temperature, away from moisture and heat. Keep out of reach of children.
- This page does not provide a dose calculator. Dosing must follow the prescriber, pharmacist, or product label.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician.
Missed dose
Unithiol treatment is supervised by the treating clinical team. If a scheduled dose is missed, contact your prescriber, pharmacist or poisons centre for guidance rather than deciding on your own; do not take an extra dose to catch up.
Overdose
In case of overdose, seek emergency medical attention immediately. Symptoms may include severe nausea, vomiting, low blood pressure, or kidney/liver dysfunction. Supportive care and monitoring are essential.
Side effects
Side effects and their urgency vary; report severe, persistent, or concerning symptoms to a healthcare professional.
Nausea
Incidence: Reported in the clinician-authored database; frequency not established
Vomiting
Incidence: Reported in the clinician-authored database; frequency not established
Diarrhea
Incidence: Reported in the clinician-authored database; frequency not established
Skin rash
Incidence: Reported in the clinician-authored database; frequency not established
Dizziness
Incidence: Reported in the clinician-authored database; frequency not established
Hypotension
Incidence: Reported in the clinician-authored database; frequency not established
Elevated liver enzymes
Incidence: Reported in the clinician-authored database; frequency not established
Serious warnings
Serious allergic reactions can occur, including anaphylaxis — serious
Symptoms: Serious allergic reactions can occur, including anaphylaxis. May cause kidney or liver dysfunction; regular monitoring is required. Use with caution in patients with pre-existing renal or hepatic impairment. May interact with other medications, especially those affecting the kidneys. Not recommended during pregnancy or breastfeeding unless clearly needed.
Action: Follow the urgency stated and seek prompt or emergency care when indicated.
Contraindications recorded in the clinician database — serious
Symptoms: Contraindications recorded in the clinician database: Contraindications include known hypersensitivity to DMPS or other chelating agents, and severe renal impairment due to risk of accumulation and toxicity. Caution is advised in patients with hepatic dysfunction, pre-existing blood dyscrasias, or those at risk for allergic reactions. Monitor closely in pregnancy and lactation.
Action: Follow the urgency stated and seek prompt or emergency care when indicated.
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Recorded interactions | Unithiol may interact with other chelating agents, certain antibiotics, and mineral supplements. It can reduce the effectiveness of mineral-based medications and may increase the risk of toxicity when combined with nephrotoxic or hepatotoxic drugs. Always inform your healthcare provider of all medications and supplements you are taking. |
Pregnancy, breastfeeding, kidney/liver function, age
Pregnancy
Unithiol is not FDA-approved in the US (it is used off-label/compounded here and is an approved drug — as Dimaval — in some other countries for heavy-metal poisoning). Safety in human pregnancy has not been established in controlled studies; use in pregnancy should be reserved for situations where the risk of untreated heavy-metal poisoning outweighs the unknown risk of the chelator, decided by a medical toxicologist.
Breastfeeding
Safety during breastfeeding has not been established for unithiol. Use during lactation should be directed by a medical toxicologist weighing the mother's poisoning severity against the unknown infant exposure risk.
Children
Frequency: Every 8 hours. Weight Based: 10 mg/kg/dose, not to exceed 300 mg per dose.. Max Daily Dose: 900 mg. Max Single Dose: 300 mg. Age Restrictions: Not recommended for pediatric use.
Renal_impairment
Renal impairment: unithiol and its metal complexes are eliminated predominantly by the kidney, so severe renal insufficiency requires caution and, in some poisoning cases, concurrent dialysis; unithiol has also been used as an adjunct to hemodialysis in anuric metal-poisoning cases under specialist toxicology supervision. Hepatic impairment: unithiol is not FDA-approved and formal hepatic dose-adjustment data are not established in the toxicology references reviewed; renal and hepatic function should both be monitored during chelation therapy.
Hepatic_impairment
Renal impairment: unithiol and its metal complexes are eliminated predominantly by the kidney, so severe renal insufficiency requires caution and, in some poisoning cases, concurrent dialysis; unithiol has also been used as an adjunct to hemodialysis in anuric metal-poisoning cases under specialist toxicology supervision. Hepatic impairment: unithiol is not FDA-approved and formal hepatic dose-adjustment data are not established in the toxicology references reviewed; renal and hepatic function should both be monitored during chelation therapy.
Monitoring
Storage
Store per the compounding pharmacy's or product labeling's instructions (typically room temperature, protected from light); as unithiol is not an FDA-approved product in the US, storage conditions depend on the specific compounded or imported formulation dispensed.
Professional information
Clinician-facing context only. This section does not replace current product labeling.
General
Indication: Mercury poisoning
Dose summary: Initial dose of 300 mg orally, followed by 300 mg every 8 hours for 2 days.
Renal context: Renal excretion is the predominant elimination route for unithiol and its metal complexes, so caution is warranted when administering it to patients with severe renal insufficiency (toxicology references note dose reduction or avoidance may be needed). Published reports support using unithiol as an adjunct to high-flux hemodialysis/hemodiafiltration in patients with anuric renal failure caused by mercury or bismuth poisoning, but this is specialist toxicology practice, not a routine outpatient dose table.
Frequently asked questions
What is Unithiol used for?
Unithiol is primarily used to treat poisoning from heavy metals such as mercury, arsenic, and lead. It binds to these metals and helps remove them from the body.
How does Unithiol work?
Unithiol acts as a chelating agent, attaching to heavy metal ions in the body and forming complexes that are then excreted in the urine.
Can children take Unithiol?
Yes, Unithiol can be used in children for heavy metal poisoning, but dosing is based on body weight and must be closely monitored by a healthcare professional.
What are the most common side effects?
Common side effects include mild rash, nausea, headache, and gastrointestinal upset. Serious reactions are rare but require immediate medical attention.
Is Unithiol safe during pregnancy?
Unithiol should only be used during pregnancy if the potential benefits outweigh the risks. Discuss with your healthcare provider before use.
Can I take mineral supplements with Unithiol?
Avoid taking mineral supplements (such as zinc, copper, or iron) unless directed by your doctor, as Unithiol may interfere with their absorption.
What should I do if I experience an allergic reaction?
Seek emergency medical attention immediately if you develop symptoms such as swelling, difficulty breathing, or severe rash. Let the clinician you see advise on whether to continue or stop taking Unithiol.
What happens if I take too much Unithiol?
Taking too much Unithiol can lead to severe adverse effects, including kidney damage, allergic reactions, and electrolyte imbalances. If an overdose is suspected, it is critical to seek immediate emergency medical attention. Prompt medical intervention is necessary to manage symptoms and prevent serious complications associated with excessive chelating agent administration.
Can I drink alcohol while taking Unithiol?
It is generally advisable to avoid alcohol consumption while taking Unithiol. Alcohol can exacerbate some side effects of chelating agents, potentially increasing the risk of liver or kidney strain. Furthermore, alcohol may interfere with the body's ability to excrete heavy metals, potentially reducing the effectiveness of Unithiol. Always consult your healthcare provider for personalized advice.
What is the mechanism of action of Dimercaptopropane sulfonate (DMPS)?
Unithiol (DMPS) is a water-soluble chelating agent containing two sulfhydryl (–SH) groups. It binds to heavy metal ions (such as mercury, arsenic, and lead) via these groups, forming stable, non-toxic, water-soluble complexes that are excreted in the urine. This reduces the bioavailability and toxicity of the metals.
What is the generic name of Dimercaptopropane Sulfonate (DMPS)?
The generic name is Dimercaptopropane sulfonate (DMPS). It is sold under brand names including Unithiol, Chelaton, Dimaval, DMPS.
What class of drug is Dimercaptopropane sulfonate (DMPS)?
Dimercaptopropane Sulfonate (DMPS) is classed as: Chelating Agent.
References
- Unithiol prescribing informationU.S. National Library of Medicine DailyMed · United States · accessed 2026-08-03 · source 1
- Unithiol/DMPS pharmacology-toxicology overview; McGraw Hill 'Poisoning & Drug Overdose' UNITHIOL (DMPS) chapterScienceDirect (Elsevier) · United States · accessed 2026-08-07 · source 2
- The role of chelation in the treatment of arsenic and mercury poisoning (PMID 24178900, PMC3846971)PubMed / Journal of Medical Toxicology (peer-reviewed review) · International · accessed 2026-08-08 · source 3
Brand names by country
Single-ingredient Dimercaptopropane sulfonate (DMPS) names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.