Sunday, October 16, 2011

New drug for treating excess iron load in patients affected with Thalassemia receiving regular blood transfusion and who do not respond to standard chelation therapy

The fight for life for patients affected with Thalassemia does not stop with regular blood transfusion. Regular blood transfusions are required for patients affected with the disease Thalassemia major, and blood transfusion it self may cause life threatening diseases like cardiac arrhythmia and liver damage, hepatitis and heart failure, diabetes and arthritis.

These disease may develop as a result of toxic effect of accumulation of iron in to body tissue, this iron is received from transfused blood from regular blood transfusion therefore patients receiving regular blood transfusion are required to be treated with iron chelating drugs like Deferoxamine , which bind to excess iron in tissue and excrete it in urine and feces. Deferoxamine molecule was discovered from bacteria Streptomyces pilosus which produced and used Deferoxamine for transportation of iron in to bacterial cell.
Some patients do not respond favorable for chelation therapy with the standard drug Deferoxamine and overloaded iron is are not completely removed from patients body.

Deferoxamine is given in IV or subcutaneously in a high dose and for very long period ranging from 12 hours to 24 hours to get desired chelating effect , drug Deferoxamine also is irritant and must be diluted several times. It rapidly get degraded in to body. Therefore a high concentration too is required to get the desired chelating effect, allergic and anaphylactic reactions too occur in rare cases.

Some patients even do not respond favorably to chelation therapy with the standard drug.

US FDA has approved a new drug which can now be used for treating patients which do not respond favorably to standard chelation therapy. Name of the newly approved drug is Ferriprox (deferiprone).
Drug Ferriprox (deferiprone) can be administered orally, dose is 75 mg per kg of body weight per day split in to three doses. Three molecule of deferiprone form chelate with one mol of iron which is then excreted through urine and feces.

Drug Ferriprox is the first drug after 2005 to get approval from US FDA for treating patients affected with Thalassemia.

Iron from hemoglobin in RBCS from transfused blood keep on accumulating in body tissue leading to toxicity to all the tissue where ever it get accumulated like in liver leading to liver damage, in heart muscles leading to fibrosis of heart muscles causing arrhythmia and heart failure, in pancreases suppressing the formation of insulin, also other hormones like growth hormone production too is suppressed, which suppress all other hormonal levels and endocrine system hormones too.

Twelve clinical trial were conducted to evaluate safety and efficacy of drug Ferriprox and it was observed that in patients who did not respond to conventional chelation therapy , about 20% reduction in serum ferritin was observed a 20 % decrease in ferritin levels were observed.

The excess iron in our body binds with proteins and form a iron proteinate which is stored in muscles and tissues allover the body and can be broken later on and iron can be used from this source when ever it is needed.

Side effects of Ferriprox are as follows :
Neutropenia, Join pain , abdominal pain , nausea and vomiting.
One of the serious side effect is agranulocytosis , the white blood cell count goes down rendering body susceptible for other serious infections.

US FDA has approved the drug Ferriprox (deferiprone) in an accelerated drug approval process as the disease Thalassemia has very little options for treatment when standard chilation therapy is not favorable.

Drug Ferriprox (deferiprone) is marketed by Toronto based pharmaceutical company ApoPharma, US FDA has also asked ApoPharma to conduct post market studies to evaluate safety and efficacy further. And to evaluate efficacy and safety in patients with sickle cell anemia too.

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