Succimer

A mercaptodicarboxylic acid used as an antidote to heavy metal poisoning because it forms strong chelates with them. [PubChem]

Succimer is indicated for the treatment of lead poisoning in pediatric patients with blood lead levels above 45 μg/dL. Succimer is not indicated for prophylaxis of lead poisoning in a lead-containing environment; the use of Succimer should always be accompanied by identification and removal of the source of the lead exposure.

Succimer is a chelating (KEE-late-ing) agent that is used to remove a heavy metal (such as lead) from the body. Succimer binds to lead in the blood and allows it to be passed out in the urine.

Succimer is used to treat lead poisoning.

Succimer may also be used for purposes not listed in this medication guide.

Usual Pediatric Dose for Lead Poisoning - Severe

1 year or older:

Initial dose: 10 mg/kg or 350 mg/m2 orally every 8 hours for five days

Maintenance dose: 10 mg/kg or 350 mg/m2 orally every 12 hours for 14 days

8 kg to 15 kg:

Initial dose: 100 mg orally every 8 hours for five days

Maintenance dose: 100 mg orally every 12 hours for 14 days

16 kg to 23 kg:

Initial dose: 200 mg orally every 8 hours for five days

Maintenance dose: 200 mg orally every 12 hours for 14 days

24 kg to 34 kg:

Initial dose: 300 mg orally every 8 hours for five days

Maintenance dose: 300 mg orally every 12 hours for 14 days

35 kg to 44 kg:

Initial dose: 400 mg orally every 8 hours for five days

Maintenance dose: 400 mg orally every 12 hours for 14 days

45 kg or greater:

Initial dose: 500 mg orally every 8 hours for five days

Maintenance dose: 500 mg orally every 12 hours for 14 days

Repeated courses may be administered if indicated by weekly blood lead concentration levels, with a minimum of two weeks between courses unless blood lead levels indicate the need for more rapid treatment.

Renal Dose Adjustments

Data not available

Liver Dose Adjustments

Data not available

Precautions

Mild to moderate neutropenia has been reported in some patients receiving Succimer. While a causal relationship to Succimer has not been absolutely established, neutropenia has been reported with other drugs in the same chemical class. A complete blood count with white blood cell differential and direct platelet counts should be obtained prior to and weekly during Succimer therapy. Succimer should either be withheld or discontinued if the absolute neutrophil count (ANC) is below 1200/mcL, and the patient followed closely to document recovery of the ANC to above 1500/mcL or to the patient's baseline neutrophil count. In patients who develop neutropenia, there is limited experience with reexposure. Such patients should be rechallenged only if the benefit of Succimer therapy clearly outweighs the potential risk of another episode of neutropenia and then only with careful patient monitoring. Patients should be instructed to promptly report any signs of infection. If infection is suspected, the above laboratory tests should be conducted promptly.

Since the extent of clinical experience with Succimer is limited, patients should be carefully observed during treatment.

Elevated blood lead levels and associated symptoms may rapidly return following discontinuation of Succimer because of redistribution of lead from bone stores to soft tissues and blood. After therapy, patients should be monitored for rebound of blood lead levels with at least once- weekly laboratory measurements until stable. Nonetheless, the severity of lead intoxication (as measured by the initial blood lead level and the rate and degree of rebound of blood lead) should be used as a guide for more frequent blood lead monitoring.

Patients should be adequately hydrated during treatment with Succimer.

Caution should be exercised in patients with compromised renal function.

Mild, transient elevations of serum transaminases have been observed in some patients during treatment with Succimer therapy. Serum transaminases should be monitored prior to and at least weekly during therapy. Patients with a history of liver disease should be monitored closely.

Clinical experience with repeated courses of Succimer therapy is limited. The safety of uninterrupted dosing lasting longer than three weeks has not been established and is not recommended.

The possibility of allergic or other mucocutaneous reactions to Succimer should be considered, particularly upon readministration (as well as during initial courses). Patients requiring repeated courses of Succimer should be monitored during each course.

Dialysis

Data not available

Other Comments

Patients should maintain adequate hydration during Succimer therapy.

The capsule content can be given in a small amount of food if young children are unable to swallow the capsules.

See also:
What is the most important information I should know about Succimer?

Succimer can lower the activity of the immune system making you more susceptible to infection. Avoid contact with people who have colds, the flu, or other contagious illnesses. Contact your doctor immediately if you develop signs of infection such as fever, sore throat, or coughing.

Use caution when driving, operating machinery, or performing other hazardous activities. Succimer may cause drowsiness or dizziness. If you experience drowsiness or dizziness, avoid these activities.

Use Succimer as directed by your doctor. Check the label on the medicine for exact dosing instructions.

• Succimer may be taken with or without food.
• Swallow Succimer whole. Do not break, crush, or chew before swallowing.
• If you have difficulty swallowing the capsule, empty the contents onto a small amount of soft food. Eat the food right away without chewing. You may also eat the contents of the capsule from a spoon. After eating, follow with a fruit drink.
• Drinking extra fluids while you are taking Succimer is recommended. Check with your doctor for instructions.
• If you miss a dose of Succimer, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.

Ask your health care provider any questions you may have about how to use Succimer.

Use: Labeled Indications

Treatment of lead poisoning in children with serum lead levels >45 mcg/dL

Off Label Uses

Lead poisoning

Clinical experience suggests the utility of Succimer in the treatment of symptomatic lead poisoning in adult patients. Additional data are necessary to further define the role of Succimer in the treatment of this condition.

See also:
What other drugs will affect Succimer?

Succimer is not known to interact with other drugs including iron supplements; interactions have not been systematically studied. Concomitant administration of Succimer with other chelation therapy, such as CaNa ₂ EDTA is not recommended.

Drug/Laboratory Tests Interaction: Succimer may interfere with serum and urinary laboratory tests. In vitro studies have shown Succimer to cause false positive results for ketones in urine using nitroprusside reagents such as Ketostix® and falsely decreased measurements of serum uric acid and CPK.

See also:
What are the possible side effects of Succimer?

Clinical experience with Succimer has been limited. Consequently, the full spectrum and incidence of adverse reactions including the possibility of hypersensitivity or idiosyncratic reactions have not been determined. The most common events attributable to Succimer, i.e., gastrointestinal symptoms or increases in serum transaminases, have been observed in about 10% of patients. Rashes, some necessitating discontinuation of therapy, have been reported in about 4% of patients. If rash occurs, other causes (e.g. measles) should be considered before ascribing the reaction to Succimer. Rechallenge with Succimer may be considered if lead levels are high enough to warrant retreatment. One allergic mucocutaneous reaction has been reported on repeated administration of the drug. Mild to moderate neutropenia has been observed in some patients receiving Succimer. Table I presents adverse events reported with the administration of Succimer for the treatment of lead and other heavy metal intoxication.

TABLE I : INCIDENCE OF ADVERSE EVENTS IN DOMESTIC STUDIES REGARDLESS OF ATTRIBUTION OR Succimer DOSAGE

To report SUSPECTED ADVERSE REACTIONS, contact Recordati Rare Diseases Inc. at 1-888-755-8344 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.