ALLOPURINOL tablet

البلد: الولايات المتحدة

اللغة: الإنجليزية

المصدر: NLM (National Library of Medicine)

العنصر النشط:

ALLOPURINOL (UNII: 63CZ7GJN5I) (ALLOPURINOL - UNII:63CZ7GJN5I)

متاح من:

Avera McKennan Hospital

INN (الاسم الدولي):

ALLOPURINOL

تركيب:

ALLOPURINOL 300 mg

نوع الوصفة الطبية :

PRESCRIPTION DRUG

الوضع إذن:

Abbreviated New Drug Application

خصائص المنتج

ALLOPURINOL- ALLOPURINOL TABLET
AVERA MCKENNAN HOSPITAL
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DESCRIPTION
Allopurinol has the following structural formula:
Allopurinol is known chemically as 1,5-dihydro-4_H_-pyrazolo [3,4-d]
pyrimidin-4-one. It is a xanthine
oxidase inhibitor which is administered orally. Its solubility in
water at 37°C is 80.0 mg/dL and is
greater in an alkaline solution.
Each tablet for oral administration contains either 100 mg or 300 mg
of allopurinol, USP and the
following inactive ingredients: colloidal silicon dioxide, magnesium
stearate, microcrystalline
cellulose, pregelatinized starch, sodium lauryl sulfate and sodium
starch glycolate.
CLINICAL PHARMACOLOGY
Allopurinol acts on purine catabolism, without disrupting the
biosynthesis of purines. It reduces the
production of uric acid by inhibiting the biochemical reactions
immediately preceding its formation.
Allopurinol is a structural analogue of the natural purine base,
hypoxanthine. It is an inhibitor of
xanthine oxidase, the enzyme responsible for the conversion of
hypoxanthine to xanthine and of xanthine
to uric acid, the end product of purine metabolism in man. Allopurinol
is metabolized to the
corresponding xanthine analogue, oxipurinol (alloxanthine), which also
is an inhibitor of xanthine
oxidase.
It has been shown that reutilization of both hypoxanthine and xanthine
for nucleotide and nucleic acid
synthesis is markedly enhanced when their oxidations are inhibited by
allopurinol and oxipurinol. This
reutilization does not disrupt normal nucleic acid anabolism, however,
because feedback inhibition is an
integral part of purine biosynthesis. As a result of xanthine oxidase
inhibition, the serum concentration
of hypoxanthine plus xanthine in patients receiving allopurinol for
treatment of hyperuricemia is usually
in the range of 0.3 mg to 0.4 mg/dL compared to a normal level of
approximately 0.15 mg/dL. A
maximum of 0.9 mg/dL of these oxypurines has been reported when the
serum urate was lowered to
less than 2 mg/dL by high doses of allopurinol. These values