What is Cystadrops - Mercaptamine and what is it used for?
Cystadrops is an ophthalmic (eye) medicine used in patients from 2 years of age with cystinosis. Cystinosis is an inherited disease characterized by the "accumulation" in the body of a natural substance called cystine, which causes the formation of harmful crystals particularly in the kidneys and cornea (the transparent membrane that forms the anterior portion of the eye). Cystadrops is used to reduce the accumulation of cystine crystals in the cornea.
Because the number of patients with cystinosis is low, the disease is considered 'rare', and Cystadrops was designated an 'orphan medicine' (a medicine used in rare diseases) on 7 November 2008.
Cystadrops contains the active substance mercaptamine (also known as cysteamine)
How is Cystadrops - Mercaptamine used?
Cystadrops can only be obtained with a prescription. Treatment should be initiated under the supervision of a physician experienced in the treatment of cystinosis.
Cystadrops is available in the form of eye drops. The recommended dose is 1 drop in each eye 4 times a day during waking hours. The dose may be progressively decreased by your doctor to 1 drop per day based on the results of the ophthalmological examinations. Treatment should not be stopped for a long time.
For more information, see the package leaflet
How does Cystadrops - Mercaptamine work?
Damage resulting from the accumulation of cystine crystals within corneal cells can cause severe vision problems. The active substance in Cystadrops, mercaptamine, reacts with cystine, dissolving it and forming substances that can be eliminated from the cells. When applied to the eye, the amount of cystine present in the cells of the cornea is reduced and eye damage is limited.
What benefit has Cystadrops - Mercaptamine shown during the studies?
Cystadrops was compared with another less concentrated mercaptamine-based eye drop solution in one main study involving 32 patients from 2 years of age with cystinosis. The main measure of effectiveness was based on the reduction in corneal cystine crystals observed at microscope and quantified with a score called IVCM between 0 and 28 (where 0 corresponded to the "absence of crystals). At the start of the study, patients in both groups had an average score of 10.
Cystadrops was more effective than the comparator in reducing corneal cystine crystals after 3 months of therapy: in patients treated with Cystadrops the IVCM score was decreased by 4.6 points, while in those treated with the comparator medicine it was reduced of 0.5 points. Cystadrops therapy also helped reduce photophobia (a sense of discomfort in the eye associated with exposure to bright light).
What are the risks associated with Cystadrops - Mercaptamine?
The most common side effects of Cystadrops (which may affect more than 1 in 10 people) are related to the eye and include pain, itchy and irritated eyes, increased lacrimation, blurred vision and hyperaemia (redness) of the eye. usually mild or moderate in intensity and are not long-lasting.
For the full list of restrictions and side effects reported with Cystadrops, see the package leaflet
Why has Cystadrops - Mercaptamine been approved?
Mercaptamine-based eye drops solutions manufactured locally at pharmacies or hospitals have been used for many years to treat ocular symptoms of cystinosis. Furthermore, a study showed that Cystadrops is effective in reducing corneal cystine crystals. The medicine also improved other symptoms of cystinosis such as photophobia. Regarding safety, side effects affecting the eye, although very frequent, are usually manageable.
The Agency's Committee for Medicinal Products for Human Use (CHMP) decided that Cystadrops's benefits are greater than its risks and recommended that it be approved for use in the EU.
What measures are being taken to ensure the safe and effective use of Cystadrops - Mercaptamine?
The recommendations and precautions to be observed by healthcare professionals and patients for Cystadrops to be used safely and effectively have been set out in the summary of product characteristics and package leaflet.
More information about Cystadrops - Mercaptamine
For the complete version of the Cystadrops EPAR, please consult the Agency's website: ema.europa.eu/Find medicine / Human medicines / European public assessment reports. For more information about Cystadrops therapy, read the package leaflet (included with the EPAR) or contact your doctor or pharmacist.
The summary of the opinion of the Committee for Orphan Medicinal Products for Cystadrops is available on the Agency's website: ema.europa.eu/Find medicine / Human medicines / Rare disease designation.
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