Posology : מינונים

4.2   Posology and method of administration

CYSTAGON treatment should be initiated under the supervision of a physician experienced in the treatment of cystinosis.

The goal of therapy is to keep leucocyte cystine levels below 1 nmol hemicystine/mg protein. White blood cell (WBC) cystine levels should therefore be monitored to adjust the dose. The WBC levels should be measured 5 to 6 hours after dosing and should be checked frequently when initiating therapy (e.g. monthly) and every 3-4 months when on a stable dose.

•     For children up to age 12 years, CYSTAGON dosing should be on the basis of body surface area (g/m2/day). The recommended dose is 1.30 g/m2/day of the free base divided four times daily.
•     For patients over age 12 and over 50 kg weight, the recommended CYSTAGON dose is 2 g/day, divided four times daily.

Starting doses should be 1/4 to 1/6 of the expected maintenance dose, increased gradually over 4- 6 weeks to avoid intolerance. The dose should be raised if there is adequate tolerance and the leucocyte cystine level remains >1 nmol hemicystine/mg protein. The maximum dose of CYSTAGON used in clinical trials was 1.95 g/m2/day.
The use of doses higher than 1.95 g/m2/day is not recommended (see section 4.4).

Digestive tolerance of cysteamine is improved when the medicinal product is taken just after or with food.

In children who are at risk of aspiration, aged approximately 6 years and under, the hard capsules should be opened and the content sprinkled on food. Experience suggests that foods such as milk, potatoes and other starch based products seem to be appropriate for mixing with the powder. However, acidic drinks, e.g. orange juice, should generally be avoided as the powder tends not to mix well and may precipitate out.

Patients on dialysis or post-transplantation:
Experience has occasionally shown that some forms of cysteamine are less well tolerated (i.e. leading to more adverse events) when patients are on dialysis. A closer monitoring of the leucocyte cystine levels is recommended in these patients.

Patients with hepatic insufficiency:
Dose adjustment is not normally required; however, leucocyte cystine levels should be monitored.