What is Cystagon?

Cysteamine eye drops is used to treat cystine crystal buildup in the cornea (front part of the eye) of patients with cystinosis. Cystinosis is a hereditary disorder that causes an accumulation of the amino acid cystine within cells, forming crystals that can build up and damage the eyes. This medicine works by removing the extra cystine from the cornea.

This medicine is available only with your doctor's prescription.

Your eye doctor will tell you how much of this medicine to use and how often. Do not use more medicine or use it more often than your doctor tells you to.

If you or your child are wearing contact lenses, remove them before you use cysteamine eye drops. Wait for at least 15 minutes before putting the contact lenses back in. Talk to your eye doctor about this if you have questions.

To use the eye drops:

• First, wash your hands. Tilt the head back and, pressing your finger gently on the skin just beneath the lower eyelid, pull the lower eyelid away from the eye to make a space. Drop the medicine into this space. Let go of the eyelid and gently close the eyes. Do not blink. Keep the eyes closed for 1 or 2 minutes to allow the medicine to be absorbed by the eye.
• Immediately after using the eye drops, wash your hands to remove any medicine that may be on them.
• To keep the medicine as germ-free as possible, do not touch the applicator tip to any surface (including the eye). Also, always keep the container tightly closed.

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

• For ophthalmic dosage form (eye drops):
  • For cystine crystal buildup in the cornea:
    • Adults—Use one drop in each eye, every waking hour.
    • Children—Use one drop in each eye, every waking hour.

If you miss a dose of this medicine, apply it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Store the bottle in its original carton in the freezer. Allow the bottle to reach room temperature before use. You may store the thawed bottle in the refrigerator or at room temperature; do not refreeze. Throw away any unused medicine after 7 days.

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Appropriate studies performed to date have not demonstrated pediatrics-specific problems that would limit the usefulness of cysteamine eye drops in children.

Although appropriate studies on the relationship of age to the effects of cysteamine eye drops have not been performed in the geriatric population, no geriatric-specific problems have been documented to date.

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

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.

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following is usually not recommended, but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use this medicine, or give you special instructions about the use of food, alcohol, or tobacco.

• Ethanol

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

• Brain disease or
• Head injury, history of or
• Increased pressure in the head—Use with caution. May make these conditions worse.

Your eye doctor will check your or your child's eyes at regular visits to make sure it is working properly and is not causing unwanted effects.

If your or your child's symptoms do not improve within a few days or if they become worse, check with your doctor.

If you hurt your eye, develop an eye infection, or need to have eye surgery, talk with your doctor right away. You or your child may need to change your medicine or stop using it.