Allopurinol GPO

Allopurinol GPO





Full Prescribing Info
Each tablet contains Allopurinol 100 mg.
Pharmacology: Allopurinol inhibits xanthine oxidase, the enzyme that catalyses the conversion of hypoxanthine to xanthine and of xanthine to uric acid. Oxypurinol, a metabolite of allopurinol also inhibits this enzyme. Thus, following allopurinol administration; decrease in serum and urine uric acid concentrations could be obtained. In addition, allopurinol also enables more hypoxanthine and xanthine to be reutilized in purine metabolic cycle; resulting in decreases de novo purine biosynthesis. So, allopurinol exhibits its uricosuric action via decreasing urate formation which lead to a reduction in uric acid/urate concentration in both body fluid and urine.
Following oral administration approx. 80-90% of the drug is absorbed from the gastrointestinal tract. Peak plasma concentrations of allopurinol are reached 0.5-2 hours after a usual dose 300 mg. The half-lives of allopurinol and oxypurinol are about 1-3 hours and 18-30 hours, respectively. Both allopurinol and oxypurinol are not bound to plasma protein but they are distributed into milk. About 10% of the administered drug is excreted in urine as allopurinol, about 70% as oxypurinol and an additional 20% appears in feces as unchanged drug.
Management of primary and secondary gout via lowering serum and urinary uric acid concentrations.
Prevention and/or reduction of the severity of hyperuricemia, tissue urate deposits and secondary uric acid nephropathy associated with myeloproliforative neoplastic disease, after cancer chemotherapy or radiation therapy.
Management of recurrent calcium oxalate renal calculi.
Dosage/Direction for Use
Allopurinol is administered orally, usually in a single dally dose, preferably after meals. But when the dose is higher than 300 mg/day, the drug should be given in divided doses.
Adults:Management of gout: Initially oral 100 mg once a day. The daily dose could be increased by 100 mg/day at weekly intervals, until the serum urate concentration falls to 60 μg/ml. But not to exceed 800 mg/day.
In mild gout: The usual adult dose in 200-300 mg/day.
In moderately severe gout: 400-600 mg/day.
Neoplastic disease therapy:Initial oral 600-800 mg/day starting 2-3 days prior to initiation of chemotherapy or radiation therapy.
Recurrent renal calculi: Oral 100-200 mg 1-4 times daily or 300 mg as single dose once a day.
Children:Management of Gout and Neoplastic disease therapy: up to 6 years of age oral 50 mg three times a day, 6-10 years of age oral 100 mg three times a day or 300 mg as a single dose.
(based on the Ministry of Public Health Announcement): Discontinue the drug and consult the physician immediately if there is skin rashes or flu-like syndrome.
It is contraindicated in patients with known hypersensitivity to the drug.
Discontinue the drug and consult the physician when getting any of these symptoms, maybe Stevens-Johnson syndrome, e.g., fever; skin rashes; blistering; peeling skin, such as mouth, throat, nose, sexual organ; and conjunctivitis.
Special Precautions
The drug should be discontinued at the first appearance of rash or any allergic sign.
Prophylactic doses of colchicine should be administered concurrently during the first 3-6 months of allopurinol therapy since allopurinol may increase the frequency of gouty attack during the first 6-12 months.
Use with caution in patients with liver and/or kidney dysfunction.
Use in Pregnancy: The drug should be used during pregnancy only when clearly needed.
Use in Lactation: Use with caution in nursing women.
Use In Pregnancy & Lactation
Use in Pregnancy: The drug should be used during pregnancy only when clearly needed.
Use in Lactation: Use with caution in nursing women.
Side Effects
The common side-effects are pruritic maculopapular rash, urticaria, erythematous dermatitis, alopecia, fever, malaise. The incidence of rash may be increased in patients with renal insufficiency. Allergic reactions include fever, chill, leukopenia, eosinophilia, arthralgia, rash, pruritus, nausea and vomiting. Reversible hepatomegaly, hepatitis, jaundice and kidney dysfunction have also been reported. Neuritis, peripheral neuropathy, headache, somnolence are rarely occurred.
ATC Classification
M04AA01 - allopurinol ; Belongs to the class of preparations inhibiting uric acid production. Used in the treatment of gout.
Tab 100 mg x 50 x 10's.
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