Pharmacy Guide
Patient leaflets and SmPCs, drug interaction checker, official dosages and NHS pharmacy opening hours — all in one place.
Pharmacy Guide
Patient leaflets and SmPCs, drug interaction checker, official dosages and NHS pharmacy opening hours — all in one place.
Cystadrops 3.8 mg/mL eye drops solution
⚠ This medicine appears to have been discontinued
The electronic medicines compendium (emc) no longer publishes a Summary of Product Characteristics for this product, which usually means it is no longer marketed in the UK. The patient leaflet below is kept for reference, but the product may not be available.
If you were prescribed this medicine, other products containing Mercaptamine hydrochloride may still be available. Do not stop your treatment — ask your pharmacist or GP what to use instead.
What it is and what it is used for
for
What Cystadrops is Cystadrops is an eye drops solution that contains the active substance cysteamine (also known as mercaptamine). What it is used for It is used to reduce the quantity of cystine crystals in the surface of the eye (cornea) in adults and children from 6 months of age with cystinosis. What is cystinosis Cystinosis is a rare hereditary disease in which the body is unable to remove excess cystine (an amino acid), causing cystine crystals to accumulate in various organs (such as kidney and eyes). Accumulation of crystals in the eye can lead to increased sensitivity to light (photophobia), corneal deterioration (keratopathy) and loss of vision . 2.
What you need to know before you take it
e Cystadrops
Do not use Cystadrops If you are allergic to cysteamine or any of the other ingredients of this medicine (listed in section 6). Warnings and precautions Talk to your doctor or pharmacist before using Cystadrops. Other medicines and Cystadrops Tell your doctor or pharmacist if you are using, have recently used or might use any other medicines. Pregnancy and breast-feeding Even if the level of Cystadrops in the blood is negligible, precautions should be taken. If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medicine. 1
Driving and using machines You may find that your vision is blurred for a few minutes just after using Cystadrops. Do not drive or use machines until your vision is clear. Cystadrops contains benzalkonium chloride This medicine contains 5 micrograms benzalkonium chloride in each drop which is equivalent to 0.1 mg/ml. Benzalkonium chloride may be absorbed by soft contact lenses and may change the colour of the contact lenses. You should remove contact lenses before using this medicine and put them back 15 minutes afterwards. Benzalkonium chloride may also cause eye irritation, especially if you have dry eyes or disorders of the cornea (the clear layer at the front of the eye). If you feel abnormal eye sensation, stinging or pain in the eye after using this medicine, talk to your doctor. 3.
How to take it
Cystadrops
Always use this medicine exactly as your doctor or pharmacist has told you. Check with your doctor or pharmacist if you are not sure. Recommended dose
- The recommended dose is 1 drop in each eye, 4 times a day during waking hours.
- The recommended interval between each application is 4 hours (for example, you can have your eye drops at 8.00 am, 12.00 am, 4.00 pm and 8.00 pm).
- To avoid sticky eyes in the morning, it is recommended to apply the last drop of the day at least 30 minutes before going to bed.
- The dose may be gradually decreased (to a minimum total daily dose of 1 drop in each eye) by your doctor based on eye examinations. Only use the drops in your eyes (ocular use). To use the eye drops, please follow the instructions below carefully. Those instructions are also available as an animated movie on www.cystadrops.net Step 1: Before using a vial for the first time
- Cystadrops must be brought back at room temperature before the first administration. It will facilitate the use of the drops.
- Immediately before using a vial for the first time, write the date of opening in the space provided on the carton box.
- Wash your hands carefully in order to avoid contamination by bacteria of the content in the vial.
- Remove the green protective cap (picture 1).
- Remove the metal seal (picture 2).
- Remove the grey stopper (picture 3) from the vial.
- Do not touch the opening of the vial after removing the grey stopper.
2
remove
remove green protective cap
remove grey stopper
metal seal
vial
•
Take the dropper out of its sachet, without touching the end intended to be attached to the vial, and attach it (picture 4) to the vial. Do not remove the dropper from the vial. small white cap turn and push to attach
small white cap
dropper
dropper
vial
vial
•
Make sure that you do not lose the small white cap (picture 5) that comes on the top of the dropper.
Step 2: Before using the eye drops
- Check the opening date that you wrote down on the carton box. Cystadrops can be used for up to 7 days from the time of opening.
- Get the dropper bottle and a mirror.
- Wash your hands. Step 3: Using the eye drops
- Hold the dropper bottle, pointing down, between your thumb and fingers. Move firmly the dropper bottle up and down to facilitate the filing of the dropper.
- Unscrew the small white cap from the dropper.
- Tilt your head back. Pull down your eyelid with a clean finger, until there is a "pocket" between the eyelid and your eye. The drop will go in here (picture 6).
•
Bring the dropper bottle tip close to the eye. Use the mirror if it helps. 3
• • •
Do not touch your eye or eyelid, surrounding areas or other surfaces with the dropper. It could infect the drops. Gently squeeze the dropper to release one drop of Cystadrops at a time. Take special care not to touch the tip of the dropper with your fingers. After using Cystadrops, press a finger into the corner of your eye by the nose (picture 7), then gently massage your upper eyelid to spread the eye drops over the eye.
• • •
To avoid potential irritation, remove excess medicine around the eye with a moist tissue (picture 8). Repeat the step 3 for the other eye. Replace the small white cap on the dropper immediately after use.
Step 4: Storing the eye drops after use
- Place the dropper bottle into the carton box.
- Keep Cystadrops at room temperature (it will facilitate the use of the dropper).
- Discard 7 days after opening. If a drop misses your eye Try again. If you use Cystadrops with another eye medicine Ensure that there is at least a 10 minute gap between using Cystadrops and the other eye medicine. Administer eye ointments last. If you wear soft contact lenses Do not use the drops with your lenses in. After using the drops wait 15 minutes before putting your lenses back in. If you use more Cystadrops than you should If you put too many drops in your eyes, rinse your eyes out, preferably with saline solution (or if not available with warm water). Do not put in any more drops until it is time for your next regular dose. If you forget to use Cystadrops Wait for your next scheduled application and then continue with your regular routine. Do not use a double dose to make up for a forgotten dose. If you stop using Cystadrops Cystadrops must be used every day for the medicine to work properly. If you stop using Cystadrops, cystine crystals accumulation in the eye (cornea) may increase and lead to increased sensitivity to light 4
(photophobia), corneal deterioration (keratopathy) and loss of vision. Therefore talk to your doctor before stopping this treatment. If you have any further questions on the use of this medicine, ask your doctor or pharmacist. 4.
Possible side effects
Like all medicines, this medicine can cause side effects, although not everybody gets them. You can usually carry on taking the drops, unless the effects are serious. If you are worried, talk to your doctor or pharmacist. Do not stop using Cystadrops without speaking to your doctor. The following side effects were reported: Very common side effects (may affect more than 1 in 10 people)
- eye pain
- eye redness, eye itching, eye irritation (burning)
- watery eyes
- blurred vision
- discomfort where the drops have been instilled (mainly sticky eyes and sticky eyelashes), medicine deposit on the eyelashes, around the eyes Common side effects (may affect up to 1 in 10 people)
- abnormal sensation in eye, a feeling of something in the eye
- dry eyes
- swollen eyelid
- irritation of eyelid
- visual impairement
- pain where the drops have been instilled
- stye Reporting of side effects If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the national reporting system Yellow Card Scheme Website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store. By reporting side effects you can help provide more information on the safety of this medicine. 5.
How to store it
Cystadrops
Keep this medicine out of the sight and reach of children. Do not use this medicine after the expiry date which is stated on the vial label and the carton after EXP. Before opening:
- Store in a refrigerator (2°C – 8°C).
- Keep the vial in the outer carton in order to protect from light. After first opening:
- Write down the date you opened the vial in the space on the carton.
- Cystadrops can be used for up to 7 days from the time of opening.
- Keep the dropper bottle tightly closed in the outer carton in order to protect from light. 5
• • •
Store below 25°C. Do not refrigerate. You must throw away the dropper bottle 7 days after you first opened it even if it is not empty. Use a new vial.
Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help protect the environment. 6.
Contents of the pack and other information
What Cystadrops contains The active substance is cysteamine (mercaptamine), as hydrochloride. One mL of eye drops solution contains 3.8 mg of cysteamine. The other ingredients are benzalkonium chloride (see section 2 under 'Cystadrops contains benzalkonium chloride'), disodium edetate, carmellose sodium, citric acid monohydrate, sodium hydroxide, hydrochloric acid and water for injections. What Cystadrops looks like and contents of the pack Cystadrops is a clear and viscous eye drops solution. Each box contains:
- 1 amber glass vial containing 5 mL of eye drops solution,
- 1 dropper applicator. Cystadrops is available in pack containing 1 box or in multipack containing 4 boxes. Not all pack sizes may be marketed in your country Marketing Authorisation Holder Recordati Rare Diseases Tour Hekla 52 Avenue du Général de Gaulle 92800 Puteaux France Manufacturer Recordati Rare Diseases Tour Hekla 52 Avenue du Général de Gaulle 92800 Puteaux France or Recordati Rare Diseases Eco River Parc 30, rue des Peupliers F-92000 Nanterre France For any information about this medicine, please contact the local representative of the Marketing Authorisation Holder: United Kingdom Recordati Rare Diseases UK Ltd. 6
Tel: +44 (0)1491 414333 This leaflet was last revised in 11/2025
7
Frequently asked questions about Cystadrops 3.8 mg/mL eye drops solution
How do I take Cystadrops 3.8 mg/mL eye drops solution?
Cystadrops 3.8 mg/mL eye drops solution comes as eye drops containing 3.8mg/ml. Always follow the dose your doctor or pharmacist has given you, and read the leaflet that comes with the medicine.
What is the active substance in Cystadrops 3.8 mg/mL eye drops solution?
The active substance in Cystadrops 3.8 mg/mL eye drops solution is mercaptamine hydrochloride.
Where does this information come from?
This leaflet reproduces the patient information leaflet approved for Cystadrops 3.8 mg/mL eye drops solution, as published on the electronic medicines compendium (emc). The version printed inside your medicine’s packaging is the one that applies to you.
Can I get Cystadrops 3.8 mg/mL eye drops solution without a prescription?
Whether a medicine is available over the counter or on prescription only depends on its licence. Check the leaflet, or ask your pharmacist — they can tell you straight away.
About this leaflet
The text above reproduces the patient information leaflet approved for this medicine, restructured for easier reading.
- Source: electronic medicines compendium (emc), Datapharm
- Active substance: mercaptamine hydrochloride
- Official document: view the original leaflet on emc →
⚕For healthcare professionals — Summary of Product Characteristics (SmPC)Full SmPC: dosage, interactions, contraindications, warnings+
4.1. Therapeutic indications
Cystadrops is indicated for the treatment of corneal cystine crystal deposits in adults and children from 6 months of age with cystinosis.
4.2. Posology and method of administration
Treatment with Cystadrops should be initiated under the supervision of a physician experienced in the management of cystinosis.
Posology
The recommended dose is one drop in each eye, 4 times a day during waking hours. The recommended interval between each instillation is 4 hours. The dose could be decreased progressively (to a minimum total daily dose of 1 drop in each eye) depending on the results of ophthalmic examination (such as, corneal cystine crystal deposits, photophobia).
If the patient misses an instillation, the patient should be told to continue the treatment with the next instillation.
The dose should not exceed 4 drops a day in each eye.
The accumulation of corneal cystine crystals increases if Cystadrops is discontinued. The treatment should not be stopped.
Paediatric population
Cystadrops may be used in paediatric patients from 6 months of age at the same dose as in adults (see section 5.1).
The safety and efficacy of Cystadrops in children aged less than 6 months has not been established. No data are available.
Method of administration
For ocular use.
Before the first admnistration, in order to facilitate the administration, the patient should be told to bring back Cystadrops at room temperature. After first opening, the patient should be told to keep the dropper bottle at room temperature.
To avoid sticky eyes in the morning, the patient should be advised to apply the last drop of the day at least 30 minutes before going to bed.
To prevent contamination of the dropper tip and solution, care must be taken not to touch the eyelids, surrounding areas, or other surfaces with the dropper tip of the dropper bottle.
The patient should be told to discard the dropper bottle after 7 days of use.
In case of concomitant therapy with other topical ocular medicinal products, an interval of ten minutes should be allowed between successive applications. Eye ointments should be administered last.
4.3. Contraindications
Hypersensitivity to the active substance or to any of the excipients listed in section 6.1.
4.4. Special warnings and precautions for use
Contact lenses
Benzalkonium chloride is known to discolour soft contact lenses. Contact with soft contact lenses should be avoided. Patients should be instructed to remove contact lenses prior to the administration of the eye drops and wait at least 15 minutes before re-inserting contact lenses.
Excipents with known effect
Cystadrops contains benzalkonium chloride which may cause eye irritation.
Benzalkonium chloride, which is commonly used as a preservative in ophtalmic products, has also been reported to cause punctate keratopathy and/or toxic ulcerative keratopathy. Monitoring is required.
4.5. Interaction with other medicinal products and other forms of interaction
No interaction studies have been performed.
Since the recommended total daily dose of cysteamine base is no more than approximately 0.4% of the highest recommended oral dose of cysteamine base in any age group, no interactions with orally administered medicinal products are anticipated.
4.6. Fertility, pregnancy and lactation
The recommended total daily ocular dose of cysteamine is no more than approximately 0.4% of the highest recommended dose of oral cysteamine in any age group. Systemic exposure of cysteamine following ocular administration is therefore lower than following oral administration. Although no effects during pregnancy and breast-feeding are anticipated, since systemic exposure to cysteamine is negligible, precautions should be taken with concomitant treatment with oral cysteamine.
Pregnancy
There are no adequate data from the use of cysteamine in pregnant women. Studies in animals have shown reproductive toxicity, including teratogenesis (see section 5.3). The potential risk for humans is unknown. The effect on pregnancy of untreated cystinosis is also unknown.
Therefore, oral cysteamine should not be used during pregnancy, particularly during the first trimester, unless clearly necessary.
If a pregnancy is diagnosed or planned, the treatment should be carefully reconsidered and the patient must be advised of the possible teratogenic risk of cysteamine.
Breast-feeding
Cysteamine excretion in human's milk is unknown. However, due to the results of animal studies in breast-feeding mothers and neonates (see section 5.3), women taking oral cysteamine should not breast-feed.
Fertility
No data on the effect of cysteamine on human fertility are available. Studies in animals have shown a reduction on fertility (see section 5.3).
4.7. Effects on ability to drive and use machines
Cystadrops may have a minor influence on the ability to drive and use machines.
Temporary (in average less than 1 minute) blurred vision or other visual disturbances may affect the ability to drive or use machines.
If blurred vision occurs at instillation, the patient must wait until the vision clears before driving or using machines.
4.8. Undesirable effects
Summary of the safety profile
The most common adverse reactions are eye pain, ocular hyperaemia, eye pruritus, lacrimation increased, blurred vision or eye irritation. The majority of these adverse reactions are transient and most are mild or moderate.
Tabulated list of adverse reactions
The following adverse reactions were reported during clinical trials and the French NPU programme with Cystadrops. Reported adverse reactions are listed below, by system organ class and by frequency (by patient).
Frequencies are defined as: very common (≥ 1/10), common (≥ 1/100 to < 1/10), uncommon (≥ 1/1 000 to < 1/100), rare (≥ 1/10 000 to < 1/1 000), very rare (< 1/10 000), not known (cannot be estimated from the available data).
System organ class
Adverse reactions
Eye disorders
Very common : eye pain, vision blurred, eye irritation, ocular hyperaemia, eye pruritus, lacrimation increased, deposit eye
Common : abnormal sensation in eye, dry eye, foreign body sensation in eye, eyelid oedema, eyelid irritation, visual impairment, hordeolum
General disorders and administration site conditions
Very common : instillation site discomfort (mainly sticky eyes and sticky eyelashes)
Common : instillation site pain
Paediatric population
Frequency, type and severity of adverse reactions in children are the same as in adults.
74 paediatric patients were followed through clinical trials and the French NPU programme. 5 patients were below 2 years old , the youngest was 13 months old, 19 patients were under 6 years old, 21 between 6 and 12 years old and 29 between 12 and 18 years old.
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the national reporting system Yellow Card Scheme. Website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.
4.9. Overdose
Overdose is unlikely to occur with ocular administration.
In case of accidental ingestion, monitoring and symptomatic management of the patient should be implemented.
🇷🇴 Known in Romania as
Medicines sold in Romania with the same active substance: Cunoscut în România ca
- CYSTADROPS 3,8 mg/ml prescriptionMERCAPTAMINUM · eye / ear / nose
Same active substance. The strength, the form and whether you need a prescription can differ. Always ask a pharmacist before you switch. Romanian medicines in the UK →
🇵🇱 Known in Poland as
Medicines sold in Poland with the same active substance: W Polsce znany jako
- CystadropsMercaptamini hydrochloridum · eye / ear / nose
Same active substance. The strength, the form and whether you need a prescription can differ. Always ask a pharmacist before you switch. Polish medicines in the UK →
💬 Ask about this leaflet
Ask anything about Cystadrops 3.8 mg/mL eye drops solution. The assistant answers only from this leaflet — if the leaflet does not cover it, it will say so. It does not give medical advice.
Answers come from the patient leaflet published on the electronic medicines compendium (emc). They are not medical advice. Ask a pharmacist or your GP if you are unsure. For urgent help call NHS 111, or 999 in an emergency.