Cystagon (cysteamine) is a cystine depleting agent. It's used in adults and children to treat a rare genetic condition called nephropathic cystinosis, which is a build-up of cystine (a protein) in the kidneys. This medication is available as immediate-release capsules that are taken whole by mouth every 6 hours. But if you're having trouble swallowing, or if Cystagon (cysteamine) is prescribed for a child under 6 years old, the contents of capsules can be sprinkled on food and consumed. Common side effects include vomiting, low appetite, and weakness.
Buildup of cystine in the kidneys (nephropathic cystinosis) in children and adults
Cystinosis is a genetic condition where there's a build-up of cystine (a protein) in the body. This happens because lysosomes, which are parts of the cell that are responsible for breaking down cystine, aren't working properly.
Cystagon (cysteamine) is a cystine depleting agent. It works by attaching to lysosomes to help them work better at removing cystine from your body.
Source:Â DailyMed
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
More common
Watering of the eyes
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Lowers cystine levels by about 50% after a dose
Works well to protects your kidneys from cystine build-up
Capsules can be opened and sprinkled onto food for people who have trouble swallowing pills
Can be used in children of all ages
Needs to be taken 4 times per day
Requires routine lab tests
Can't be taken during pregnancy
Can't be taken by people who have an allergy to penicillamine (Depen)
Mark your appointments in your calendar to see your provider to be examined and get any blood tests done. This will help make sure you're being properly monitored to see how well Cystagon (cysteamine) is working and how safe it is for you.
Your provider will order blood tests that measure your cystine levels about every 3 months during treatment to see how well Cystagon (cysteamine) is working for you. They'll also monitor your liver function tests and blood cell counts to make sure they're within normal range.
If you're having trouble swallowing the capsules, sprinkle the contents of the capsule over food and take the dose. Also do this for a child under 6 years old who's prescribed Cystagon (cysteamine) because they're at high risk for choking on the capsule.
Take Cystagon (cysteamine) four times per day at about the same times every day. You can take Cystagon (cysteamine) with or without food. But nausea is a common side effect, so taking it with food might help.
If you miss a dose of Cystagon (cysteamine), take it as soon as you remember. But if it's within 2 hours of your next dose, skip the missed dose and take your next dose as you would regularly. Don't double up the dose to make up for the missed dose.
Cystagon (cysteamine) can make you sleepy and dizzy, which can affect your ability to focus. It can also cause weakness and confusion. Don't drive or do anything that requires concentration until you know how this medication makes you feel.
Avoid drinking alcohol because it can worsen side effects from Cystagon (cysteamine), such as upset stomach, sleepiness, depression, and dizziness. It can also affect how well the medication works in your body.
Tell your provider if you notice a skin rash while taking Cystagon (cysteamine). They'll make sure the rash isn't a sign of a more severe skin problem. You'll likely need to stop the medication until the rash clears.
Cystagon (cysteamine) raises the risk of stomach bleeding, so tell your provider right away if you experience unexplained vomiting, stomach pain, dark-colored stools, or blood in your vomit or stool.
Cystagon (cysteamine) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
People have reported skin rashes after starting Cystagon (cysteamine). Sometimes, these rashes are temporary and go away after the medication is stopped. But rarely, this medication can cause life-threatening skin reactions, such as toxic epidermal necrolysis (TEN). Let your provider know right away if you notice changes in your skin such as rash, blisters, skin reddening, or skin peeling. Depending on how serious your reaction is, your provider might ask you to temporarily stop Cystagon (cysteamine) and restart you at a lower dose, or stop this medication completely.
Some people have also reported purplish skin lesions after taking higher doses of Cystagon (cysteamine). Sometimes, they've also experienced other skin changes, bone pain, and higher risk of fracture along with these lesions. Your provider will examine your skin and bones regularly when you're taking Cystagon (cysteamine). If needed, they'll lower your dose of the medication.
Risk factors: Older age | History of stomach bleeding or ulcers | Bleeding problems | Liver problems | Taking other medications that raise your risk of bleeds | Drinking alcohol | Smoking
Cystagon (cysteamine) can raise your risk for serious stomach problems, including bleeding and ulcers (sores). Stomach bleeding is a dangerous condition that requires treatment right away. Your risk for stomach bleeds is even higher if you're taking Cystagon (cysteamine) with other medications that can put you at risk, such as blood thinners (anticoagulants). Seek medical help right away if you're feeling faint, vomiting blood, have bloody or dark stools, or have severe stomach pain or discomfort that doesn't go away while you're taking Cystagon (cysteamine).
Cystagon (cysteamine) can affect your brain, which can cause symptoms, such as sleepiness, depression, fatigue, seizures, and brain swelling. Don't drive or do anything that requires you to focus until you know how this medication affects you. Let your provider know if you experience any of these symptoms because they might prescribe a lower dose of Cystagon (cysteamine).
Although very rare, there have been a few reports of Cystagon (cysteamine) causing high blood pressure in the blood vessels in the brain, or intracranial hypertension. This can lead to changes in vision and cause symptoms like headache, nausea, vomiting, dizziness, and ringing in the ears. Your provider will likely perform eye examinations before and regularly throughout treatment with Cystagon (cysteamine), including looking at your eyes for papilledema (or eye swelling).
Your provider will typically prescribe a lower dose of Cystagon (cysteamine) to start, then raise it slowly over 4 to 6 weeks until you've reached the recommended maintenance dose.
People ages 12 years and older (weighing 110 lbs or more): The typical maintenance dose is 500 mg by mouth every 6 hours.
People under 12 years old (weighing 110 lbs or less): Your child's provider will calculate their dose based on body surface area (BSA), which takes into account your child's height and weight. In general, the maintenance dose ranges from 100 mg to 450 mg by mouth every 6 hours.
Your provider will adjust your dose based on how well the medication is lowering your cystine levels and if you're having side effects.
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.
Allergic reaction to penicillamine (Depen) or Procysbi (cysteamine bitartrate)
Buildup of cystine in the kidneys (nephropathic cystinosis) in children and adults
Buildup of cystine in the kidneys (nephropathic cystinosis) in adults and children (ages 1 year and older)
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Chen, J. J. (2024). Papilledema. Merck Manual Consumer Version.
Cystinosis Research Network. (n.d.). About cystinosis.
Mylan Pharmaceuticals Inc. (2021). Cystagon- cysteamine bitartrate capsule [package insert]. DailyMed.
National Eye Institute. (2023). Idiopathic intracranial hypertension.
National Human Genome Research Institute. (2024). Lysosome.
National Kidney Foundation. (n.d.). Kidney failure.
National Kidney Foundation. (n.d.). Nephropathic cystinosis: Evaluation and management.
National Kidney Foundation. (n.d.). Nephropathic cystinosis.
van Stein, C., et al. (2021). A comparison of immediate release and delayed release cysteamine in 17 patients with nephropathic cystinosis. Orphanet Journal of Rare Diseases.
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