Allopurinol reduces the production of uric acid in your body. Uric acid buildup can lead to gout or kidney stones.
Allopurinol is used to treat gout or kidney stones, and to decrease levels of uric acid in people who are receiving cancer treatment.
Allopurinol may also be used for purposes not listed in this medication guide.
Important information
Do not use allopurinol if you have ever had a serious allergic reaction to allopurinol. Stop taking the medicine and call your doctor at once if you have any signs of skin rash, no matter how mild. Take each dose with a full glass of water. To reduce your risk of kidney stones forming, drink 8 to 10 full glasses of fluid every day, unless your doctor tells you otherwise.
Allopurinol can lower blood cells that help your body fight infections. This can make it easier for you to bleed from an injury or get sick from being around others who are ill. Your blood may need to be tested often. Visit your doctor regularly.
Avoid drinking alcohol. It can make your condition worse. Allopurinol may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.
Before taking this medicine
You should not take allopurinol if you are allergic to it.
To make sure you can safely take allopurinol, tell your doctor if you have any of these other conditions:
FDA pregnancy category C. It is not known whether allopurinol will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication. Allopurinol can pass into breast milk and may harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.
See also: Pregnancy and breastfeeding warnings (in more detail)
How should I take allopurinol?
Take allopurinol exactly as prescribed by your doctor. Do not take in larger or smaller amounts or for longer than recommended. Follow the directions on your prescription label.
Your doctor may occasionally change your dose to make sure you get the best results.
Take each dose with a full glass of water. To reduce your risk of kidney stones forming, drink 8 to 10 full glasses of fluid every day, unless your doctor tells you otherwise. You may have gout attacks more often when you first start taking allopurinol. Your doctor may recommend other gout medication to take with allopurinol. Keep using your medication as directed and tell your doctor if your symptoms do not improve after a few months of treatment.
Allopurinol can lower blood cells that help your body fight infections. This can make it easier for you to bleed from an injury or get sick from being around others who are ill. Your blood may need to be tested often. Visit your doctor regularly.
Store allopurinol at room temperature away from moisture and heat.
What happens if I miss a dose?
Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
What should I avoid?
Avoid being near people who are sick or have infections. Tell your doctor at once if you develop signs of infection.
Allopurinol may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert. Avoid drinking alcohol. It may worsen your condition.
Your doctor may recommend a special diet to help treat your condition. Follow your diet and medication routines very closely.
Allopurinol side effects
Get emergency medical help if you have any of these signs of an allergic reaction to allopurinol: hives; difficult breathing; swelling of your face, lips, tongue, or throat. Stop using allopurinol and call your doctor at once if you have a serious side effect such as:
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fever, sore throat, and headache with a severe blistering, peeling, and red skin rash;
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the first sign of any skin rash, no matter how mild;
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pain or bleeding when you urinate;
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nausea, upper stomach pain, itching, loss of appetite, weight loss, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);
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urinating less than usual or not at all;
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joint pain, flu symptoms;
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severe tingling, numbness, pain, muscle weakness; or
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easy bruising, unusual bleeding (nose, mouth, vagina, or rectum), purple or red pinpoint spots under your skin.
Less serious allopurinol side effects may include:
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
See also: Side effects (in more detail)
Allopurinol dosing information
Usual Allopurinol Adult Dose for Gout:
Initial: 100 mg orally once a day.
Maintenance: 200 to 300 mg (mild gout) orally once a day or 400 to 600 mg/day (moderately severe tophaceous gout) in divided doses.
Usual Allopurinol Adult Dose for Hyperuricemia Secondary to Chemotherapy:
Initial:
Parenteral: 200 to 400 mg/m2/day to a maximum of 600 mg/day
Oral: 600 to 800 mg/day for 1 to 3 days with consumption of at least 2 L of fluid/day.
Maintenance:
200 to 300 mg/day orally until patient no longer at high risk for developing hyperuricemia.
Usual Allopurinol Adult Dose for Calcium Oxalate Calculi with Hyperuricosuria:
Initial: 200 to 300 mg orally once a day.
Maintenance: 300 mg/day or less.
Usual Adult Dose for Congestive Heart Failure:
Study (n=11) to prevent the formation of superoxide free radicals and improve endothelial function (in NYHA class II to III chronic heart failure): 300 mg orally daily for 1 month
Usual Allopurinol Adult Dose for Cardiothoracic Surgery:
Studies: Coronary Artery Bypass Graft Surgery
600 mg orally one day prior to surgery and another 600 mg orally the day of surgery.
Usual Adult Dose for Leishmaniasis:
Study (n=31 - Cutaneous leishmaniasis: 20 mg/kg/day plus low-dose meglumine antimoniate (30 mg/kg/day) for 20 days.
Case Reports - Visceral leishmaniasis, post renal transplant: 300 mg daily plus meglumine antimoniate (50 mg/kg/day)
Usual Allopurinol Adult Dose for Mania:
Case Reports -- Mania (bipolar I) associated with hyperuricemia: 300 mg orally daily.
Usual Allopurinol Adult Dose for High Risk Percutaneous Transluminal Angioplasty:
Study (n=38) - Primary Percutaneous Transluminal Coronary Angioplasty (PTCA):
400 mg orally administered immediately after admission to the emergency department (approximately 60 minutes before reperfusion) and after primary PTCA was completed.
Usual Allopurinol Adult Dose for Reactive Perforating Collangenosis:
Case Report: 100 mg orally daily.
Usual Pediatric Dose for Hyperuricemia Secondary to Chemotherapy:
Parenteral :
Less than or equal to 10 years: 200 mg/m2/day in 1 to 3 equally divided doses not to exceed 600 mg/24 hours. All doses greater than 300 mg should be given in equally divided doses.
Greater than 10 years: 200 to 400 mg/m2/day administered in 1 to 3 equally divided doses, not to exceed 600 mg/24 hours.
Oral:
Less than 6 years: 150 mg/day orally in 3 divided doses.
6 to 10 years: 300 mg/day orally in 2 to 3 divided doses.
Greater than 10 years: 600 to 800 mg/day in 2 to 3 equally divided doses
Usual Allopurinol Pediatric Dose for Leishmaniasis:
Greater than 5 years old
Study (n=31) - Cutaneous leishmaniasis: 20 mg/kg/day plus low-dose meglumine antimoniate (30 mg/kg/day) for 20 days.
What other drugs will affect allopurinol?
Tell your doctor about all other medicines you use, especially:
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azathioprine (Imuran);
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chlorpropamide (Diabinese);
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cyclosporine (Gengraf, Sandimmune, Neoral);
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mercaptopurine (Purinethol);
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an antibiotic such as ampicillin (Principen, Omnipen, others) or amoxicillin (Amoxil, Augmentin, Trimox, Wymox);
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a blood thinner such as dicoumarol or warfarin (Coumadin); or
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a diuretic (water pill).
This list is not complete and other drugs may interact with allopurinol. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor.
