cysteamine ophthalmic (Rx)

>10%

Cystaran

• Sensitivity to light
• Redness
• Eye pain/irritation
• Headache
• Visual field defects

Cystadrops

• Eye pain
• Vision blurred
• Eye irritation
• Ocular hyperemia
• Instillation site discomfort
• Eye pruritus
• Lacrimation increased
• Ocular deposits

Contraindications

None

Cautions

For topical ophthalmic use only

Avoid touching eyelids or surrounding areas with the dropper tip of the bottle to avoid contamination

Benign intracranial hypertension (pseudotumor cerebri) reported with cysteamine PO; there have also been reports associated with cysteamine ophthalmic, however, all of these patients were on concurrent cysteamine PO

Contains benzalkonium chloride, which may be absorbed by soft contact lenses; contact lenses should be removed prior to application and may be reinserted after 15 minutes

Pregnancy

There are no adequate and well-controlled studies of ophthalmic cysteamine in pregnant females to inform any drug associated risks

Animal data

• Oral administration of cysteamine to pregnant rats throughout organogenesis was teratogenic at doses 240 to 960 times the recommended human ophthalmic dose (based on body surface area)
• Use during pregnancy only if potential benefit justifies potential risk to the fetus

Lactation

No information available regarding presence of cysteamine in human milk, the effects on the breastfed infants, or the effects on milk production

Cysteamine administered orally is present in milk of lactating rats

Unknown whether measurable levels of cysteamine would be present in maternal milk following topical ocular administration

Pregnancy Categories

A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

NA: Information not available.

Mechanism of Action

Acts as a cystine–depleting agent by converting cystine to cysteine-cysteamine mixed disulfides and reduces corneal cystine crystal accumulation

Absorption

Negligible; incremental increase in systemic cysteamine levels derived from cysteamine ophthalmic applied topically to the eye in patients treated with oral cysteamine was observed to be negligible

Ophthalmic Preparation

Wash hands carefully in order to avoid microbiological contamination

Do not touch opening of bottle or dropper

Cystaran

• Each week, remove one new bottle from the freezer
• Allow bottle to thaw completely (~24 hr) before use

Cystadrops

• Remove from refrigerator
• Remove green protective cap, metal seal, and gray stopper from the bottle
• Advise not to lose the small white cap that comes on the top of the dropper; keep the small white cap tightly closed when not in use

Ophthalmic Administration

Topical ophthalmic use only

Tilt head back

Pull down lower eyelid with a clean finger and look up; allow drop to go into the space between lower eyelid and eye

Do not touch dropper tip to the eyelids, surrounding areas, or any surface, as this may contaminate solution

Concomitant use with topical ocular products

• Allow an interval of 10 minutes between successive applications
• Administer eye ointments last

Contact lenses

• Remove before using drops
• Wait at least 15 minutes after using drops, before reinserting contact lenses back in eyes

Missed dose

• Administer a dose as soon as feasible and then continue treatment with next scheduled instillation

Storage

Cystadrops

• Unopened bottle: Refrigerate at 2-8ºC (36-46ºF) in the original carton
• Opened bottle: After first opening, store at room temperature at 20-25ºC (68-77ºF) for up to 7 days; do not refrigerate; discard after 7 days of use

Cystaran

• Unopened: Store in freezer at -25 to -15ºC (-13 to 5ºF) in the original carton
• Thawed bottle: Store at 2-25ºC (36-77ºF) for up to 7 days; do not refreeze; discard after 7 days of use