Chemet

Keep out of reach of pediatric patients. CHEMET (succimer) is not a substitute for effective abatement of lead exposure.

Mild to moderate neutropenia has been observed in some patients receiving succimer. While a causal relationship to succimer has not been definitely 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 treatment with succimer. Therapy should either be withheld or discontinued if the absolute neutrophil count (ANC) is below 1200/µL and the patient followed closely to document recovery of the ANC to above 1500/µL or to the patient's baseline neutrophil count. There is limited experience with reexposure in patients who have developed neutropenia. Therefore, 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 treated with succimer should be instructed to promptly report any signs of infection. If infection is suspected, the above laboratory tests should be conducted immediately.

Before taking succimer, talk to your doctor if you have

• had a previous reaction to treatment with succimer;
• blood problems;
• kidney problems; or
• liver problems.

You may not be able to take succimer, or you may require a dosage adjustment or special monitoring during treatment.

Succimer is in the FDA pregnancy category C. This means that it is not known whether it will be harmful to an unborn baby. Do not take succimer without first talking to your doctor if you are pregnant or could become pregnant during treatment.

It is not known whether succimer passes into breast milk and if it will affect a nursing baby. Do not take succimer without first talking to your doctor if you are breast-feeding a baby.

You should not use succimer if you are allergic to it.

To make sure succimer is safe for you, tell your doctor if you have:

• kidney disease;

• liver disease; or

• if you have been treated with dimercaprol or edetate calcium disodium in the past month.

It is not known whether succimer will harm an unborn baby. Tell your doctor if you are pregnant.

It is not known whether succimer passes into breast milk or if it could harm a nursing baby. You should not breast-feed while using this medicine.

Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not take this medicine in larger or smaller amounts or for longer than recommended.

To make swallowing easier, you may open the succimer capsule and sprinkle the medicine into a spoonful of soft food. Swallow right away without chewing. Do not save the mixture for later use.

You may also open the capsule and empty the medicine beads into a spoon, swallow all of the beads, and then drink a glass of juice or fruit-flavored drink.

Drink plenty of liquids to keep your kidneys working properly so they can help eliminate the lead from your body.

Succimer is usually given daily for 19 days in a row. You may need to receive more than one course of treatment. Use succimer regularly to get the most benefit. Get your prescription refilled before you run out of medicine completely.

Use this medicine for the full prescribed length of time. Your symptoms may improve before the lead is completely cleared from your body.

While using succimer, you may need frequent blood tests. Your blood work will help your doctor determine how long to treat you with succimer. Your kidney function may also need to be checked.

Call your doctor if your symptoms do not improve, or if they get worse while using succimer.

Succimer can lower blood cells that help your body fight infections. This can make it easier for you to get sick from being around others who are ill. Your blood cells may need to be tested often.

Store at room temperature away from moisture and heat.

Once it has been determined how or where you got lead poisoning, avoid coming into contact with that source or location.

Avoid being near people who are sick or have infections. Tell your doctor at once if you develop signs of infection.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

• fever, cold or flu symptoms, cough, trouble breathing;

• skin sores, rash; or

• swollen gums, painful mouth sores, pain when swallowing.

Common side effects may include:

• nausea, vomiting, loss of appetite;

• diarrhea; or

• metallic taste in your mouth.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Absorption

Bioavailability

Absorption is rapid and variable, with peak plasma concentrations obtained at 1–2 hours.a

Elimination

Metabolism

Approximately 90% of absorbed dose is metabolized to mixed succimer-cysteine disulfides.a

Elimination Route

Unabsorbed drug excreted principally in feces; absorbed drug excreted principally in the urine as metabolites.a

Half-life

Approximately 2 days.a

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
• Signs of infection like fever, chills, very bad sore throat, ear or sinus pain, cough, more sputum or change in color of sputum, pain with passing urine, mouth sores, or wound that will not heal.
• A burning, numbness, or tingling feeling that is not normal.
• Rectal irritation.
• Ear pain.

Chemet (succimer) is an orally active, heavy metal chelating agent. The chemical name for succimer is meso 2, 3-dimercaptosuccinic acid (DMSA). Its empirical formula is C 4H 6O 4S 2 and molecular weight is 182.2. The meso-structural formula is:

Succimer is a white crystalline powder with an unpleasant, characteristic mercaptan odor and taste.

Each Chemet opaque white capsule for oral administration contains beads coated with 100 mg of succimer and is imprinted black with Chemet 100. Inactive ingredients in medicated beads are: povidone, sodium starch glycolate, starch and sucrose. Inactive ingredients in capsule are: gelatin, iron oxide, titanium dioxide and other ingredients.

Succimer has been assigned to pregnancy category C by the FDA. High-dose animal studies have showed evidence of fetotoxicity and teratogenicity. There are no controlled data in human pregnancy. Succimer is only recommended for use during pregnancy when benefit outweighs risk.

There are no data on the excretion of succimer into human milk. The effects in the nursing infant are unknown. Because many drugs and heavy metals are excreted into human milk, the manufacturer recommends that nursing mothers requiring succimer be discouraged from nursing.