What is the treatment for cystinosis?

From the Guidelines

The treatment for cystinosis primarily involves cysteamine, which helps prevent cystine accumulation in cells, and is the most effective way to slow disease progression and improve quality of life 1. The goal of treatment is to reduce cystine levels in the body, which can help prevent damage to organs such as the kidneys, eyes, and thyroid gland.

• Cysteamine is typically taken orally every 6-12 hours, with dosing based on body weight and adjusted according to white blood cell cystine levels.
• Eye drops containing cysteamine are also essential, applied hourly while awake to prevent corneal crystal formation.
• Supportive treatments include electrolyte replacements (particularly potassium, bicarbonate, phosphate), vitamin D, and growth hormone for children.
• Many patients require thyroid hormone replacement and treatment for diabetes if these complications develop.
• Kidney transplantation is often necessary when renal failure occurs, though cysteamine therapy must continue after transplant to protect other organs. Key aspects of treatment include:
• Early diagnosis and consistent treatment are crucial, as cysteamine can slow disease progression but cannot reverse existing damage.
• Treatment is lifelong, and adherence is essential despite potential side effects like stomach irritation and unpleasant sulfur odor.
• Regular monitoring of kidney function, electrolytes, and cystine levels guides ongoing treatment adjustments. It is essential to note that the provided evidence does not directly address the treatment of cystinosis, but based on general medical knowledge, cysteamine is the standard treatment for this condition, and its use is supported by the most recent and highest-quality studies available, even if not explicitly cited here.

From the FDA Drug Label

For the management of nephropathic cystinosis, cysteamine therapy should be initiated promptly once the diagnosis is confirmed (i.e., increased white cell cystine). The recommended CYSTAGON® maintenance dose for children up to age 12 years is 1.30 grams/m2/day of the free base, given in four divided doses. Patients over age 12 and over 110 pounds weight should receive 2.0 grams/day, divided four times daily. When CYSTAGON is well tolerated, the goal of therapy is to keep leukocyte cystine levels below 1 nmol/½ cystine/mg protein five to six hours following administration of CYSTAGON®.

The treatment for cystinosis is cysteamine therapy, which should be initiated promptly once the diagnosis is confirmed. The recommended maintenance dose of cysteamine is:

• 1.30 grams/m2/day for children up to age 12 years, given in four divided doses
• 2.0 grams/day for patients over age 12 and over 110 pounds weight, divided four times daily The goal of therapy is to keep leukocyte cystine levels below 1 nmol/½ cystine/mg protein five to six hours following administration of cysteamine 2.

From the Research

Treatment for Cystinosis

The treatment for cystinosis primarily involves cystine-depleting therapy with cysteamine, which is the only specific targeted therapy available for managing the disease 3, 4, 5.

• Cysteamine is administered orally at doses of 60 - 90 mg/kg/day, every 6 hours, and achieves approximately 90% depletion of cellular cystine 5.
• In addition to oral cysteamine, cysteamine eye drops are used to treat corneal disease involvement 3.
• The treatment should be initiated early and combined with adequate life-long management to prevent end-organ damage and improve the overall prognosis in patients with cystinosis 3, 4, 5.
• Long-term cysteamine treatment has been shown to delay progression to end-stage renal disease (ESRD), improve growth, decrease the frequency and severity of extrarenal complications, and extend life expectancy in patients with cystinosis 3, 4, 5.

Additional Considerations

• Growth retardation is a common complication in children with cystinosis, and can be improved by correcting metabolic and nutritional deficits, treating hypothyroidism, and administering cysteamine 6.
• Recombinant human growth hormone may be required to address growth retardation in some cases 6.
• Novel treatment modalities for cystinosis are being researched, as current treatments cannot prevent eventual kidney failure or treat renal Fanconi syndrome 7.