Succimer is a prescription medication, chemically known as dimercaptosuccinic acid (DMSA). It is primarily used to treat poisoning caused by the ingestion or absorption of certain heavy metals. Developed as a chelating agent, its function is to bind with these harmful metals within the body, facilitating their removal. The U.S. Food and Drug Administration (FDA) approved it for pediatric use in 1991.
Medical Uses of Succimer
Succimer is indicated for treating lead poisoning, particularly in children who have blood lead levels measured at or above 45 micrograms per deciliter (µg/dL). Lead is a potent neurotoxin that can cause irreversible damage to the brain and nervous system, especially in young children whose bodies are still developing. Removing lead from the bloodstream is important to mitigate ongoing damage to various organs and tissues. The use of this medication should always be paired with the identification and elimination of the source of lead exposure.
Beyond its primary application for lead, succimer is also used to treat poisoning from other heavy metals, such as mercury and arsenic, in adult populations. The ability of succimer to bind to these specific metals makes it a valuable tool in toxicology. While it is effective in these cases, its use is carefully considered by medical professionals based on the specific circumstances of the poisoning.
How Succimer Works in the Body
The therapeutic action of succimer is based on a chemical process called chelation. Succimer molecules act like claws that specifically seek out and bind to heavy metal ions circulating in the bloodstream and stored in tissues. The drug’s molecular structure contains dithiol groups, which are sulfur-containing components that form strong, stable bonds with these metal ions. This binding action effectively neutralizes the toxic metals, preventing them from interacting with and damaging sensitive cellular components.
Once succimer has bound to a metal ion, it forms a new, water-soluble compound or complex. The newly formed succimer-metal complex can be efficiently filtered out of the blood by the kidneys. Subsequently, the complex is expelled from the body through urine, which reduces the overall burden of the heavy metal. This mechanism provides a direct pathway to eliminate harmful substances that the body cannot otherwise clear effectively.
Administration and Dosing
Succimer is administered orally, typically in the form of a 100 mg capsule. As a prescription-only medication, it must be taken under the close supervision of a healthcare provider. The capsules should be stored at room temperature, away from light and excessive heat.
The dosing regimen for succimer is highly individualized. A physician determines the correct dose based on the patient’s body weight and the severity of the poisoning, which is confirmed through blood tests that measure the level of the specific heavy metal. Treatment typically follows a structured schedule, often lasting for about 19 days. It is common for the dosage to be higher at the beginning of the treatment course and then tapered off in later stages. Completing the full course as prescribed is necessary to ensure the most effective detoxification.
Potential Side Effects and Monitoring
Treatment with succimer can be associated with a range of side effects. The most common are gastrointestinal issues, including nausea, vomiting, diarrhea, and a loss of appetite. Some individuals may also experience a skin rash or notice an unusual, often metallic, taste in their mouth. These effects are generally transient and resolve after the treatment period.
Less frequently, more serious side effects can occur, necessitating immediate medical attention. These can include a decrease in the number of neutrophils, a type of white blood cell that helps fight infection, a condition known as neutropenia. Changes in liver function tests may also be observed, indicating potential stress on the liver.
Doctors regularly order blood tests throughout the course of succimer therapy. These tests are used to monitor blood cell counts, assess liver and kidney function, and track the declining levels of the heavy metal in the blood. This vigilant oversight allows medical professionals to adjust treatment as needed and manage any adverse effects promptly, ensuring the benefits of detoxification outweigh the potential risks.