CYSTADROPS

Cystinosis is a rare disease caused by mutations in the CTNS gene that encodes for cystinosin, a protein responsible for transporting cystine out of the cell lysosome.

A defect in cystinosin function is followed by cystine accumulation throughout the body, especially the eyes and kidneys.

Several preparations of cysteamine exist for the treatment of cystinosis manifestations, some in capsule form, and others in ophthalmic solution form. 10, 12 In particular, cystine deposits on the eye can cause significant discomfort throughout the day and require frequent treatment with eye drops, typically every waking hour.

On August 25th 2020, the first ophthalmic solution for cystinosis requiring only 4 daily treatments was granted FDA approval.

Cysteamine eye drops are a practical and effective option for those affected by ocular cystinosis.

Inc., CYSTADROPS® reduce the burden of multiple frequent medications normally administered to those with cystinosis.

The bitartrate salt of cysteamine is used for the oral treatment of nephropathic cystinosis and cystinuria in adults and in children aged ≥6 years 12.

The hydrochloride salt, formulated as ophthalmic drops, is indicated for the treatment of corneal cystine crystal accumulation in patients with cystinosis 9, 10.

Approved by the

EMA for the treatment of corneal cystine crystal accumulation in adults and in children aged ≥6 months with cystinosis

Cystine accumulation is the cause of organ damage in cystinosis.

Cysteamine prevents the accumulation of cystine crystals in the body and is specifically prescribed to prevent kidney and eye damage. 4, 9, 12 Cysteamine converts cystine into a form that may easily exit cells, preventing harmful accumulation.

Individuals born without the ability to metabolize cystine suffer from cystinosis, a rare genetic disorder characterized by the widespread accumulation of cystine crystals throughout the body and eye tissues.

The cystine crystals may cause considerable damage, particularly in the renal tissues and corneal tissues.

In some cases, renal failure can occur during childhood if the condition is left untreated.

Other organs that may be affected by cystinosis include the CNS, thyroid, pancreas, muscle tissues, and gonads.

Cysteamine converts cystine to cysteine and cysteine-cysteamine mixed disulfides, reducing the buildup of corneal cystine crystals.

This drug participates in a thiol-disulfide interchange reaction with lysosomes, leading to cysteine exit from the lysosome in patients diagnosed with cystinosis.

Target Actions Organism U Somatostatin binder Humans U Cystine cleavage Humans U Neuropeptide Y receptor type 2 other/unknown Humans.

Oral administered cysteamine is absorbed in the gastrointestinal tract and reaches its maximum plasma concentration in about 1.4 hours, with some variation according to the type of formulation (delayed versus immediate-release). 6, 5, 12 One pharmacokinetic study of adults with Cystic Fibrosis revealed a Cmax of 2.86 mg/L.

The maximum plasma concentration after administration of cysteamine eye drops is unknown, however, it is likely to be considerably lower than oral administration.

According to prescribing information, the AUC 0-12 h for the delayed-release oral tablets is 99.26 ± 44.2 μmol*h/L with a Cmax of 27.70 ± 14.99 μmol/L.

AUC 0-12 for the immediate-release tablets is 192.00 ± 75.62 μmol*h/L with a Cmax of 37.72 ± 12.10 μmol/L.

Cysteamine has a volume of distribution of about 129 L, according to one pharmacokinetic study.

Prescribing information indicates a volume of distribution of 382 L for the delayed-release formulation and 198 L for the immediate-release preparation.

It is known to cross the blood-brain barrier.

There is limited information in the literature regarding the metabolism of cysteamine.

The half-life of cysteamine is about 3.7 hours.

The plasma clearance of cysteamine is about 1.2-1.4 L/min.

One reference mentions a clearance of 89.9 L/h in patients with Cystic Fibrosis.

Improve decision support & research outcomes With structured adverse effects data, including: blackbox warnings, adverse reactions, warning & precautions, & incidence rates.

View sample adverse effects data in our new Data Library! See the data Improve decision support & research outcomes with our structured adverse effects data.

Two cases of human overdoses with cysteamine are recorded in the literature, according to prescribing information.

In one case, vomiting was immediate after the administration of cysteamine, and the patient did not experience other symptoms.

A 200-250 mg/kg dose was accidentally ingested by a healthy 13-month-old child.

Vomiting and dehydration followed.

A full recovery was made after hospitalization and the replenishment of fluids.

There is no known antidote for an overdose with cysteamine.

In the case of an overdose, provide supportive treatment, especially to the cardiovascular and respiratory systems.

Hemodialysis may be useful in some cases due to the fact that cysteamine has poor plasma protein binding.