Cysteamine
Cysteamine is a cystine-depleting agent used primarily to treat cystinosis, a rare genetic disorder that causes abnormal accumulation of cystine crystals in cells throughout the body. It works by converting toxic cystine into a form that can be more easily eliminated, helping to reduce damage to organs such as the kidneys and eyes.
Cysteamine treats cystinosis by reducing toxic cystine buildup in cells through conversion to cysteine and mixed disulfides.
Key facts at a glance
- ATC
- A16AA04
- RxNorm
- 3022
- Generic
- Cysteamine
- Class
- atc-a16
- Brands
- Cystaran, Procysbi, Cystagon, Cystadrops
- Availability
- rx
- Lactation
- unknown
- Routes
- ophthalmic, oral
- Forms
- solution, capsule
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Cystinosis (nephropathic form), a rare inherited storage disorder characterized by accumulation of cystine crystals in various tissues including kidneys, eyes, liver, muscles, and brain, leading to renal dysfunction and corneal deposits.
Acts as a cystine-depleting agent by converting cystine to cysteine and cysteine-cysteamine mixed disulfides, which can then be transported out of cells and reduce intracellular cystine crystal accumulation, particularly in the cornea and renal tubular cells.
Treatment is typically lifelong and should be initiated as early as possible in pediatric patients. Regular monitoring of white blood cell cystine levels may be required. Must be handled with care as it can cause skin irritation and has a distinctive odor. May cause gastrointestinal side effects.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy