QUESTIONS & ANSWERS

We will have answers to more of these questions shortly. In the meantime, please feel free to email questions to cystine@ucsd.edu

1. Why is Cystagon^TM given every six hours? And how important that it be exactly every six hours?

2. Will a transplanted kidney develop cystine crystals and cause renal failure?

No. Studies have shown that trasplanted kidneys in non-cystinosis patients. In addition, the cystine crystals found in transplanted kidneys of cystinosis patients are in the host cells, which have migrated into the donor kidneys, and are not derived from the donor kidneys themselves. (Bill Gahl)

3. Can Cystagon^TM or liquid cysteamine be added to the eye?

No. The Cystagon^TM, diluted to make it liquid, contains compounds other than cysteamine which have not been tested for use in the eye. Only specially prepared eyedrops should be used in the eye. (Bill Gahl)

4. Do carriers of the cystinosis gene have any symptoms?

5. How is cystinosis passed on? What are the chances of having a cystinotic child after the first child is born?

6. Can a female take Cystagon^TM during pregnancy?

No. We do not know if there are teratogenic effects (i.e., effects on the development of a fetus) associated with cysteamine use. (Bill Gahl)

7. Can Cystagon^TM be given while a patient is on dialysis?

8. If Cystagon^TM therapy is stopped for several days do I have to start back on the Cystagon^TM slowly?

9. If is possible to overdose on Cystagon^TM? What happens if a double dose of Cystagon^TM is given?

10. Does carnitine help patients with cystinosis? Are there any side effects of carnitine? And is the carnitine in the health food stores safe to use?

We know that oral carnatine rapidly elevates plasma carnitine levels to normal, and long-term carnitine therapy in young children prevents muscle carnitine deficiency. We have no evidence of any beneficial effects on muscle size or strength. Side effects include occasionaly nausea or upset stomach and a fish smell to the skin. The carnitine in health food stores, now that D-carnitine has been eliminated, is safer than before, but I would recommend only prescription-brand carnitine. (Bill Gahl)

11. Is it safe to take other medications with Cystagon ^TM and are there any known drug interactions with Cystagon ^TM?

It appears safe; I know of no drug interactions. (Bill Gahl)

12. What is the life expectancy of a person with cystinosis?

That has not been determined. The oldest patient with classical cystinosis is 40 years old, but as patients with early cysteamine therapy get older, they will define the life expectancy. I believe it will be normal when our 20-year old, well-treated patients get to be 70 or 80. (Bill Gahl)

13. Does cystinosis affect the immune system?

14. In which countries does cystinosis occur?

15. Can a cystinotic child outgrow the need for medications such as polycitra?

16. Pain in wrists, hands and legs?

17. Is is safe to given growth hormone to a child with cystinosis?

Yes. Many cystinosis children have recieved it with benefit. (Bill Gahl)

18. Do individuals with cystinosis have difficulties with swallowing? And is there anything to treat this problem?

19. Do cystinotics have unusual eating habits? Has anyone conducted a nutritional study?

20. Is is too late to start taking Cystagon^TM as an adult? Are there any benefits in taking Cystagon^TM as an adult?

21. Can I regulate the amount of water my child drinks?

22. What is the difference between cysteamine HCl, phosphocysteamine and cysteamine bitartrate?