Allopurinol

Generic Name: allopurinol

Xanthine Oxidase Inhibitor [EPC]Over-the-Counter (OTC)

Brand Names:

Allopurinol

Allopurinol is a xanthine oxidase inhibitor. Available as 100 mg and 300 mg scored tablets for oral administration.

Overview

Allopurinol is a xanthine oxidase inhibitor. Available as 100 mg and 300 mg scored tablets for oral administration.

Uses

Indicated for management of adults with primary or secondary gout including acute attacks and joint damage. Also used for patients with leukemia, lymphoma, and solid tumors receiving cancer therapy that elevates uric acid levels. Additionally indicated for patients with recurrent calcium oxalate calculi with elevated uric acid excretion.

Dosage

Initial dosage for gout in patients with normal kidney function is 100 mg orally daily, increasing by 100 mg weekly until serum uric acid reaches 6 mg/dL or less (maximum 800 mg daily). For patients with impaired kidney function, start 50 mg daily with gradual titration. For cancer-related hyperuricemia: Adults 300-800 mg daily.

Side Effects

Most common adverse reactions (incidence >1%) are nausea, diarrhea, and increased liver function tests. Skin rash occurs most frequently. Less common effects include hepatic necrosis, thrombocytopenia, leukopenia, Stevens-Johnson syndrome, toxic epidermal necrolysis, peripheral neuropathy, and renal failure.

Interactions

Avoid concomitant use with capecitabine and pegloticase. Reduce mercaptopurine or azathioprine dose to one-third or one-fourth when used together. Increases cyclosporine and warfarin concentrations. Thiazide diuretics, ampicillin, and amoxicillin increase skin rash risk.

Warnings

Serious and sometimes fatal dermatologic reactions including toxic epidermal necrolysis and Stevens-Johnson syndrome have been reported. Gout flares may occur during treatment initiation; concurrent prophylactic treatment with colchicine or anti-inflammatory agents is recommended. Monitor kidney function.

Pregnancy

Allopurinol may cause fetal harm. Animal studies showed adverse developmental outcomes. Limited human pregnancy data identified 2 infants with major congenital malformations in approximately 50 cases. Allopurinol and metabolite oxypurinol cross the placenta.

Storage

Store at 20°C to 25°C (68°F to 77°F). Dispense in tight, light-resistant container.

Frequently Asked Questions

What is Allopurinol used for?

Indicated for management of adults with primary or secondary gout including acute attacks and joint damage. Also used for patients with leukemia, lymphoma, and solid tumors receiving cancer therapy that elevates uric acid levels. Additionally indicated for patients with recurrent calcium oxalate calculi with elevated uric acid excretion.

What are the side effects of Allopurinol?

Most common adverse reactions (incidence >1%) are nausea, diarrhea, and increased liver function tests. Skin rash occurs most frequently. Less common effects include hepatic necrosis, thrombocytopenia, leukopenia, Stevens-Johnson syndrome, toxic epidermal necrolysis, peripheral neuropathy, and renal failure.

Can I take Allopurinol during pregnancy?

Allopurinol may cause fetal harm. Animal studies showed adverse developmental outcomes. Limited human pregnancy data identified 2 infants with major congenital malformations in approximately 50 cases. Allopurinol and metabolite oxypurinol cross the placenta.

What are the important warnings for Allopurinol?

Serious and sometimes fatal dermatologic reactions including toxic epidermal necrolysis and Stevens-Johnson syndrome have been reported. Gout flares may occur during treatment initiation; concurrent prophylactic treatment with colchicine or anti-inflammatory agents is recommended. Monitor kidney function.

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Medical Disclaimer

This drug information is for educational purposes only and should not replace professional medical advice. Drug information is sourced from the FDA National Drug Code Directory and Structured Product Labeling. Always consult with a healthcare provider before starting, stopping, or changing any medication.