Allopurinol used in all except (DNB Dec 2010)
|B||Lesch Nyhan syndrome|
|C||Neiman’s Pick disease|
a. Allopurinol is a xanthine oxidase inhibitor and the drug has several uses. It is isomer of hypoxanthine. The drug promptly lowers serum uric acid and is mobilizes tophi. The drug is of special value in overproduces.
b. It is the drug of choice for treatment of Lesch Nyhan syndrome, urate nephropathy, nephropathy in renal failure, chronic gout and hyperuricemia in tumors, patients refractory to uricosuric agents.
c. The drug is used commonly along with azathioprine to reduce the risk of tumor induced rise of blood uric aciD. Dose of drug should be reduced when used with azathioprine.
d. Allopurinol is well absorbed and gets converted into an active metabolite called oxypurinol. It has an half life of 24 hours.
e. The drug causes wide variety of side effects. Block of production of uric acid can cause retention leading to precipitation of acute attack of gout.
f. This is most common adverse effect associated with use of allopurinol (CMDT’2010, pp-735). Hypersensitivity, is more common in patients with infectious mononucleosis. Rarely, toxic epidermal necrolysis can occur.
g. Granulomatous hepatitis has been reporteD. Severe pancytopenia can also occur. Usual dose is 300 mg per day.
h. Rasburicase is a recombinant version of urate oxidase enzyme. The drug causes conversion of uric acid to allantoin, which is 5 times more water-soluble than uric acid and is promptly excreted by kidneys. The drug hence can prevent precipitation of uric acid in kidneys and possible renal failure associated with this. The drug is used for prevention and treatment of tumor lysis syndrome. Anaphylaxis and methemoglobinemia are side effects.