Succimer

Pronunciation: SUX-ih-mer
Class: Chelating agent

Trade Names

Chemet
- Capsules 100 mg

Pharmacology

Forms water soluble chelate with lead, increasing the urinary excretion.

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Pharmacokinetics

Absorption

Rapid but variable absorption with peak levels in 1 to 2 h.

Elimination

Approximately 49% of the dose excreted (39% feces, 9% urine, 1% as carbon dioxide via the lungs). Elimination t _½ about 2 days.

Indications and Usage

Treatment of lead poisoning in children with blood levels above 45 mcg/dL.

Unlabeled Uses

Treatment of heavy metal poisonings (mercury, arsenic); however, further study is needed.

Contraindications

Standard considerations.

Dosage and Administration

PO Start with 10 mg/kg or 350 mg/m ² every 8 h for 5 days. Reduce frequency of administration to 10 mg/kg or 350 mg/m ² every 12 h for an additional 14 days. A course of treatment lasts 19 days. Repeated courses may be necessary if indicated by weekly monitoring of lead blood concentration. A minimum of 14 days between courses is recommended unless lead blood levels indicate the need for more prompt treatment. In young children unable to swallow capsules, the contents of the capsule can be sprinkled on a small amount of soft food or placed on a spoon and followed with fruit drink.

Storage/Stability

Store at controlled room temperature (59° to 77°F).

Drug Interactions

Coadministration with other chelation therapy is not recommended.

Laboratory Test Interactions

May interfere with serum and urinary laboratory tests (in vitro, succimer caused false-positive results with ketones in urine using nitroprusside reagents [eg, Ketostix ] and falsely decreased serum uric acid and CPK measurements).

Adverse Reactions

Incidence of adverse reactions stated for children (unless adult is stated), most reactions occur more frequently in adults.

Cardiovascular

Arrhythmia (1.8% adults).

CNS

Head pain, heavy head/tired, head cold, headache (5.2% children, 15.7% adults); drowsiness, dizziness, sensorimotor neuropathy, sleepiness, paresthesia (1% children, 12.7% adults).

Dermatologic

Papular rash, herpetic rash, rash, mucocutaneous eruptions, pruritus (2.6% children, 11.2% adults).

GI

Nausea, vomiting, diarrhea, appetite loss, hemorrhoidal symptoms, loose stools, metallic taste in mouth (12% children, 20.9% adults); abdominal cramps, stomach pains (5.2% children, 15.7% adults).

Genitourinary

Moniliasis (5.2% children, 15.7% adults); decreased urination, voiding difficulty, proteinuria increased (3.7% adults).

Hematologic

Mild to moderate neutropenia, increased platelet count, intermittent eosinophilia (0.5% children, 1.5% adults).

Metabolic

Elevated AST, ALT, alkaline phosphatase, elevated serum cholesterol (4.2% children, 10.4% adults).

Musculoskeletal

Back pain, rib pain (5.2% children, 15.7% adults); kneecap pain, leg pains (3% adults).

Respiratory

Throat sore, rhinorrhea, nasal congestion, cough (3.7% children, 0.7% adults).

Special Senses

Cloudy film in eye, ears plugged, otitis media, eyes watery (1% children, 12.7% adults).

Miscellaneous

Chills, flank pain, fever, flu-like symptoms (5.2% children, 15.7% adults).

Precautions

Pregnancy

Category C .

Lactation

Undetermined.

Children

Safety and efficacy not established in children younger than 12 mo.

Hypersensitivity

Consider the possibility upon readministration and during the initial courses.

Renal Function

Adequately hydrate patients undergoing treatment. Use with caution in patients with compromised renal function. While succimer appears to be dialyzable, lead chelates are not.

Hepatic Function

Transient mild elevations of serum transaminases have been reported. Monitor serum transaminases before the start of therapy and at least weekly during therapy. Closely monitor patients with a history of liver disease.

Infection

If an infection is suspected, a CBC with WBC differential and direct platelet count should be obtained.

Lead poisoning

Not a substitute for effective abatement of lead exposure.

Neutropenia

Mild to moderate neutropenia has been reported; however, a causal relationship has not been established.

Rebound lead blood levels

Due to redistribution of lead from bone stores to soft tissue and blood, elevated lead blood levels and associated symptoms may return rapidly after discontinuation of succimer. Therefore, monitor for rebound lead blood levels at least weekly.

Patient Information

• Advise patient or caregiver that prescribed dose is to be taken every 8 h for 5 days and then every 12 h for 2 wk. Advise patient or caregiver that regimen may need to be repeated if blood lead levels are still elevated.
• Advise patient or caregiver that good hydration will be important during therapy.
• Instruct patient or caregiver to immediately report rash or any signs of infection to health care provider.
• Advise patient or caregiver that the source of lead exposure must be identified and removed to prevent further exposure to lead.

Copyright © 2009 Wolters Kluwer Health.