[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Chelating agents](https://durgical.com/en/pharmacology/classes/chelating-agents/) › Succimer

[Pharmacology](https://durgical.com/en/pharmacology/) · [Chelating agents](https://durgical.com/en/pharmacology/classes/chelating-agents/)

# Succimer

An oral sulfhydryl chelator (DMSA) for lead poisoning, especially in children, and for arsenic and mercury.

Updated 2026-11-01

- Class: [Chelating agents](https://durgical.com/en/pharmacology/classes/chelating-agents/)
- Target: Lead, arsenic and mercury ions
- WHO Model List of Essential Medicines

Also called: DMSA, meso-2,3-dimercaptosuccinic acid

## Mechanism of action

Succimer is a water-soluble analogue of dimercaprol with two sulfhydryl groups. It binds lead, arsenic and mercury in water-soluble chelates that are excreted in urine, lowering blood lead. It has a higher therapeutic index than dimercaprol and, because it is oral, it is the usual choice for lead poisoning in children without encephalopathy.

- Taken by mouth and absorbed
- Two -SH groups bind lead, arsenic or mercury
- Water-soluble chelates leave in urine
- Blood lead falls; exposure must also stop

## Pharmacokinetics

**Absorption**
Absorbed by mouth

**Elimination**
Kidneys, as metal chelates

## Indications

- Lead poisoning, particularly in children, where edetate is avoided [Lead poisoning →](https://durgical.com/en/conditions/lead-poisoning/)
- Arsenic poisoning [Arsenic poisoning →](https://durgical.com/en/conditions/arsenic-poisoning/)
- Inorganic, elemental and organic mercury poisoning [Mercury poisoning →](https://durgical.com/en/conditions/mercury-poisoning/)

## Adverse effects

### Common

- Rash
- Raised liver enzymes
- Eosinophilia

### Serious (rare, important)

- Neutropenia

## Contraindications

- Previous hypersensitivity to succimer

## Key interactions

**Continued exposure to lead**
Chelation does not replace removing the source; levels rise again if exposure continues

## What is monitored

- Blood lead before, during and after each course
- Liver enzymes
- Complete blood count (neutrophils)
- Kidney function

## Administration and safety

- Taken by mouth; the capsule can be opened and mixed with soft food for children who cannot swallow it
- The patient is well hydrated before treatment

## Nursing care

- Teach the family how to give the capsule contents with food
- Report rash, fever or sore throat
- Help identify the lead source at home or work
- Schedule follow-up blood lead tests

## Pregnancy and breastfeeding

Data are limited (category C in the Colombian guide); breastfeeding is stopped until blood lead has fallen.

## Memory aid

Succimer = «suck the metal» by mouth: oral DMSA for kids with lead, no needle needed.

## Test yourself

Think of the answer, then tap the question to see it.

## What advantage does succimer have over dimercaprol and edetate?

It is taken by mouth and has a higher therapeutic index, so it suits children with lead poisoning without encephalopathy.

## Which laboratory tests are followed during succimer treatment?

Blood lead, liver enzymes, blood count and kidney function.

## What must accompany chelation in lead poisoning?

Finding and removing the source of exposure.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/succimer/)

## Related drugs

- [Dimercaprol](https://durgical.com/en/pharmacology/dimercaprol/)
- [Sodium calcium edetate](https://durgical.com/en/pharmacology/sodium-calcium-edetate/)

## Related conditions

- [Lead poisoning](https://durgical.com/en/conditions/lead-poisoning/)
- [Arsenic poisoning](https://durgical.com/en/conditions/arsenic-poisoning/)
- [Mercury poisoning](https://durgical.com/en/conditions/mercury-poisoning/)

[← Back to the class: Chelating agents](https://durgical.com/en/pharmacology/classes/chelating-agents/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [Guía para el Manejo de Emergencias Toxicológicas](https://minsalud.gov.co/sites/rid/Lists/BibliotecaDigital/RIDE/DE/GT/guias-manejo-emergencias-toxicologicas-outpout.pdf) (Ministerio de Salud y Protección Social; Organización Panamericana de la Salud, 2017); Farmacología básica y clínica (Katzung), 16.ª ed., cap. 57 (McGraw Hill, 2025); [eEML - Electronic Essential Medicines List](https://list.essentialmeds.org/) (World Health Organization, 2025); [DailyMed - EDETATE CALCIUM DISODIUM injection](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=710a2c8c-3620-4f6f-b8fc-fb19ab9e9f22) (DailyMed (U.S. National Library of Medicine), 2026).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/pharmacology/succimer/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/succimer/