Cystaran
(cysteamine)Dosage & Administration
Instill one drop of CYSTARAN in each eye, every waking hour.
Cystaran Prescribing Information
CYSTARAN is a cystine-depleting agent indicated for the treatment of corneal cystine crystal accumulation in patients with cystinosis.
Instill one drop of CYSTARAN in each eye, every waking hour.
Do not touch dropper tip to any surface, as this may contaminate the solution.
Discard after 1 week of use.
Ophthalmic solution containing 6.5 mg/mL of cysteamine hydrochloride equivalent to 4.4 mg/mL of cysteamine (0.44%).
Pregnancy
Risk Summary
There are no adequate and well controlled studies of ophthalmic cysteamine in pregnant women to inform any drug associated risks. Oral administration of cysteamine to pregnant rats throughout the period of organogenesis was teratogenic at doses 86 to 345 times the recommended human ophthalmic dose (based on body surface area)[see Data]. CYSTARAN should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
Data
Animal Data
Teratology studies have been performed in rats at oral doses in the range of 37.5 mg/kg/day to 150 mg/kg/day (86 to 345 times the recommended human ophthalmic dose based on a body surface area) and have revealed cysteamine bitartrate to be teratogenic. Observed teratogenic findings were intrauterine death, cleft palate, kyphosis, heart ventricular septal defects, microcephaly, exencephaly, and growth deficits.
Lactation
Risk Summary
There is no information regarding the 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. It is not known whether measurable levels of cysteamine would be present in maternal milk following topical ocular administration of CYSTARAN.
Pediatric Use
The safety and effectiveness of CYSTARAN (cysteamine ophthalmic solution) 0.44% have been established in pediatric patients.
Geriatric Use
When the clinical studies with CYSTARAN were conducted, the reduced life expectancy from cystinosis did not make it possible to include patients in the geriatric age range.
Renal Impairment
The effect of renal impairment on the pharmacokinetics of cysteamine following ophthalmic administration of cysteamine ophthalmic solution has not been evaluated because ophthalmic exposure compared to systemic exposure is negligible. The majority of the patients in the ophthalmic clinical studies are assumed to have had some degree of renal impairment due to their underlying systemic disease. The total daily ophthalmic dose is less than 2% of the recommended oral daily dose of cysteamine; thus, the systemic exposure following ophthalmic administration is expected to be negligible compared to oral administration.
None.
Contamination of Tip and Solution
To minimize contaminating the dropper tip and solution, care should be taken not to touch the eyelids or surrounding areas with the dropper tip of the bottle. Keep bottle tightly closed when not in use.
Benign Intracranial Hypertension
There have been reports of benign intracranial hypertension (or pseudotumor cerebri) associated with oral cysteamine treatment that has resolved with the addition of diuretic therapy.
There have also been reports associated with ophthalmic use of cysteamine; however, all of these patients were on concurrent oral cysteamine.
Contact Lens Use
CYSTARAN contains benzalkonium chloride, which may be absorbed by soft contact lenses. Contact lenses should be removed prior to application of solution and may be reinserted 15 minutes following its administration[see Patient Counseling Information (17)].
Topical Ophthalmic Use
CYSTARAN is for topical ophthalmic use.
Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
The safety data described below reflect exposure in controlled clinical trials of six months to 19 years duration in approximately 300 patients.
The most frequently reported ocular adverse reactions occurring in ≥10% of patients were sensitivity to light, redness, and eye pain/irritation, headache and visual field defects.
CYSTARAN is a sterile ophthalmic solution containing 6.5 mg/mL of cysteamine hydrochloride, equivalent to 4.4 mg/mL of cysteamine (0.44%) as the active ingredient. Cysteamine is a cystine-depleting agent which lowers the cystine content of cells in patients with cystinosis.
Molecular Formula: C2H7NS HCl
Molecular Weight: 113.61
Each milliliter of CYSTARAN contains: Active: cysteamine 4.4 mg (equivalent to cysteamine hydrochloride 6.5 mg); Preservative: benzalkonium chloride 0.1 mg; Inactive Ingredients: sodium chloride, hydrochloric acid and/or sodium hydroxide (to adjust pH to 4.1-4.5), and purified water.
Mechanism of Action
Cysteamine acts as a cystine-depleting agent by converting cystine to cysteine and cysteine-cysteamine mixed disulfides and reduces corneal cystine crystal accumulation.
Pharmacokinetics
The peak plasma concentration of cysteamine following ocular administration of cysteamine ophthalmic solution in humans is unknown, but it is expected to be substantially less than the peak plasma concentration following oral administration of cysteamine bitartrate.
Carcinogenesis, Mutagenesis, Impairment of Fertility
Carcinogenesis
Cysteamine has not been tested for its carcinogenic potential in long-term animal studies.
Mutagenesis
Cysteamine was not mutagenic in the Ames test. It produced a negative response in anin vitrosister chromatid exchange assay in human lymphocytes but a positive response in a similar assay in hamster ovarian cells.
Impairment of Fertility
Repeat breeding reproduction studies were conducted in male and female rats. Cysteamine was found to have no effect on fertility and reproductive performance at an oral dose of 75 mg/kg/day (173 times the recommended human ophthalmic dose based on body surface area). At an oral dose of 375 mg/kg/day (864 times the recommended human ophthalmic dose based on body surface area), it reduced the fertility of the adult rats and the survival of their offspring.
Clinical efficacy was evaluated in controlled clinical trials in approximately 300 patients. The primary efficacy end point was the response rate of eyes that had a reduction of at least 1 unit in the photo-rated Corneal Cystine Crystal Score (CCCS) at some time point during the study when baseline CCCS ≥1, or a lack of an increase of more than 1 unit in CCCS throughout the study when baseline CCCS <1.
Study 1 combined the data from three smaller studies. For eyes with a lower baseline of CCCS <1, the response rate was 13% (4/30) [95% CI: (4, 32)]. For eyes with a higher baseline of CCCS ≥1, the response rate was 32% (94/291) [95% CI: (27, 38)].
Study 2 evaluated ocular cystinosis patients who had a baseline of CCCS ≥1. The response rate was 67% (10/15) [95% CI: (38, 88)].
Study 3 also evaluated ocular cystinosis patients; for eyes with a baseline of CCCS ≥1, the response rate was 33% (3/9) [95% CI: (8, 70)].
Corneal crystals accumulate if CYSTARAN is discontinued.
Fifteen (15) mL of CYSTARAN (cysteamine ophthalmic solution) 0.44% is supplied in an opaque, white, LDPE 88 mm tall bottle with a 1.6 mm blue, silicone rubber flow-controlled dropper tip and closed with a white, high-density polyethylene (HDPE) screw cap. The bottle is foil-wrapped and stored in a carton.
NDC 54482-020-02
Storage: Store in freezer at -25°C to -15°C (-13°F to 5°F) in the original carton. Thaw for approximately 24 hours before use. Store thawed bottle at 2°C to 25°C (36°F to 77°F) for up to 1 week. The thawed bottle does not require refrigeration between use. Do not refreeze the thawed medication. Discard after 1 week of use.
Mechanism of Action
Cysteamine acts as a cystine-depleting agent by converting cystine to cysteine and cysteine-cysteamine mixed disulfides and reduces corneal cystine crystal accumulation.