Cystagon

Cystagon is a prescription medication used to treat cystinosis of the kidneys. Cystinosis is a rare condition that causes cystine, a protein building block, to build up in the cells of the body. Cystagon belongs to a class of medications called anti-cystine agents, which help by decreasing the levels of cystine in the body.

This medication comes as capsules and is usually taken by mouth four times daily. 

The most common side effects with Cystagon include vomiting, an eating disorder associated with low body weight (anorexia), and fever. Cystagon may also cause drowsiness. Do not drive or operate heavy machinery until you know how this medication will affect you.

Cystagon is a prescription medication used to treat cystinosis of the kidneys. Cystinosis is a rare condition that causes cystine, a protein building block, to build up in the cells of the body.

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

• Mylan Pharmaceuticals, Inc.

Serious side effects have been reported with Cystagon. See “Drug Precautions” section.

Common side effects of Cystagon include the following:

• vomiting
• an eating disorder associated with low body weight (anorexia)
• fever
• diarrhea
• rash

Cystagon may also cause drowsiness. Do not drive or operate heavy machinery until you know how this medication will affect you.

This is not a complete list of Cystagon side effects. Ask your doctor or pharmacist for more information.

Tell your doctor if you have any side effect that bothers you or that does not go away.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

No drug interactions have been evaluated by the manufacturer. However, you should tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements. Not all drug interactions are known or reported and new drug interactions are continually being reported. 

Serious side effects have been reported with Cystagon including the following:

• Skin rash. Tell your doctor right away if you or your child gets a skin rash. Cystagon may need to be temporarily stopped until the rash goes away. If the rash is severe, your doctor may totally stop the Cystagon.
• Central nervous system symptoms: Some patients taking cysteamine, a medicine in Cystagon, have developed seizures, depression, and become too sleepy (excessive sleepiness). Tell your doctor if you or your child has these symptoms.
• Stomach and intestinal (gastrointestinal) problems: Patients taking cysteamine, a medicine in Cystagon, have developed ulcers and bleeding. Tell your doctor right away if you or your child get stomach pain, nausea, vomiting, loss of appetite, or throw up blood.
• Low white blood cell count and abnormal liver function on blood tests. Your doctor will monitor you or your child for this.
• Benign intracranial hypertension, also called pseudotumor cerebri, has been reported. This is a condition where there is high pressure in the fluid around the brain. Tell your doctor right away if you or your child develop any of the following symptoms while taking Cystagon: headache, buzzing or "whooshing" sound in the ear, dizziness, nausea, double vision, blurry vision, loss of vision, pain behind the eye or pain with eye movement. Your doctor will monitor you or your child with eye examinations to find and treat this problem early. This will help lessen the chance of loss of eyesight.
• Skin lesions, bone lesions, and joint problems. Children treated with high doses of cysteamine, a medicine in Cystagon, may develop skin lesions. These include skin striae (which are like stretch marks), bone injuries (such as fractures), bone deformities, and joint problems. Examine your or your child's skin while taking Cystagon. Report any changes to your doctor. Your doctor will monitor you or your child for these problems.

Cystagon may cause some people to become sleepy or less alert than they are normally. You or your child should not drive, operate machinery, or do other dangerous activities until you know how Cystagon affects you.

Do not take Cystagon if you have an allergic or hypersensitive reaction to Cystagon, or any of its ingredients including cysteamine, or penicillamine.

Medicines can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of Cystagon, there are no specific foods that you must exclude from your diet when receiving Cystagon.

Before taking Cystagon, tell your doctor about all of your medical conditions. Especially tell your doctor if you:

• have had an allergic reaction to a medicine containing cysteamine or penicillamine in the past
• have a skin rash or any bone problems.
• have a history of seizures, exhaustion, depression or other nervous system problems.
• have or have had stomach or intestinal problems including ulcers or bleeding.
• have liver or blood problems.
• are pregnant or plan to become pregnant. It is not known whether Cystagon may harm your unborn baby. Do not take Cystagon during pregnancy unless you and your doctor decide that the possible benefit of taking Cystagon is more important than the risk to an unborn baby.
• It is not known if Cystagon will pass into breast milk. You and your doctor should decide whether to stop nursing or to stop taking the medicine.

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements.

Tell your doctor if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Cystagon falls into category C. There are no adequate and well-controlled studies in pregnant women. It is not known if Cystagon will harm your unborn baby. Cystagon should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus. Talk with your doctor about the benefits and risks of taking Cystagon during pregnancy.

Tell your doctor if you are breastfeeding or plan to breastfeed.

It is not known if Cystagon is excreted in human breast milk or if it will harm your nursing baby. Because many drugs are present in human milk and because of the potential for serious adverse reactions in nursing infants from Cystagon, you should not breastfeed during treatment with Cystagon. Talk with your doctor about the best way to feed your baby if you take Cystagon.

Take Cystagon exactly as prescribed. Do not increase or decrease the amount of medicine without your doctor's approval.

• Cystagon is available as a capsule and is usually taken four times a day. 
• If you or your child misses a dose of medicine, it should be taken as soon as possible. If it is within two hours of the next dose, skip the missed dose and go back to the regular dosing schedule. Do not double dose.
• Do not give intact Cystagon capsules to children under six years of age. They may not be able to swallow them and may choke. For children under six years of age, the capsule may be opened and the contents sprinkled on food. Talk to your doctor for complete directions.
• Your doctor will arrange for regular blood tests to be done to measure the amount of cystine inside white blood cells. This will help to determine the correct dose of Cystagon. Regular blood and urine tests will also be done to measure the levels of the body's important electrolytes. This will help your doctor to correctly adjust the doses of these supplements.
• Your doctor may also want to do certain tests to find out if unwanted effects are occurring. The tests are very important because serious side effects, including ulcers or bleeding in the stomach and intestines (digestive tract), can occur.

Take this medication exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.

The dose your doctor recommends may be based on the following:

• age
• weight
• if you are just starting this medicine
• how you respond to this medication

The recommended doses of Cystagon to treat cystinosis of the kidneys:

• Children up to age 12 years: 1.30 grams/m2/day of the free base, given in four divided doses.
• Patients over age 12 and over 110 pounds: 2.0 grams/day, divided four times daily.
• Patients who have not received cysteamine containing medicines before will be started on a lower dose. Then the doctor will increase the dose slowly over 4 to 6 weeks to help reduce the risk of side-effects. 

If you take too much Cystagon call your healthcare provider or local Poison Control Center, or seek emergency medical attention right away.

• Store Cystagon in a dry place away from light.
• Store Cystagon between 68° to 77°F (20° to 25°C).
• Keep this and all medicines out of the reach of children.