Dosing & Uses
Dosage Forms & Strengths
tablet
- 100mg
- 300mg
powder for injection
- 500mg/vial
Gout
Mild: 100 mg/day PO initially; increased weekly to 200-300 mg/day
Moderate to severe: 100 mg/day PO initially; increased weekly to 400-600 mg/day
Antineoplastic-Induced Hyperuricemia
PO: 600-800 mg divided q8-12hr, starting 1-2 days before chemotherapy
IV: 200-400 mg/m²/day; not to exceed 600 mg/m²/day; may administer as single infusion or in equally divided doses at 6, 8, 12 hr intervals beginning 1-2 days before chemotherapy
Dosing Considerations
Minimum PO dosage: 100-200 mg/day
Maximum PO dosage: 800 mg/day
Dosing Modifications
Renal impairment
- CrCl 10-20 mL/min: 200 mg/day
- CrCl 3-10 mL/min: 100 mg/day
- CrCl <3 mL/min: 100 mg/day at extended intervals
Dosage Forms & Strengths
tablet
- 100mg
- 300mg
powder for injection
- 500mg/vial
Hyperuricemia
10 mg/kg/day PO divided q12hr; not to exceed 600 mg/day
Antineoplastic-Induced Hyperuricemia
PO (<6 years): 150 mg/day divided q8hr
PO (6-10 years): 300 mg/day in single daily dose or divided q8hr
PO (>10 years): 600-800 mg/day, starting 1-2 days before chemotherapy
IV: 200 mg/m²/day initially, starting 1-2 days before chemotherapy
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Contraindicated (0)
Serious - Use Alternative (12)
- azathioprine
allopurinol increases levels of azathioprine by decreasing metabolism. Avoid or Use Alternate Drug. Increased risk of bone marrow toxicity.
- benazepril
benazepril increases toxicity of allopurinol by unspecified interaction mechanism. Avoid or Use Alternate Drug. May increase risk for allergic or hypersensitivity reactions to allopurinol. Monitor for symptoms of hypersensitivity reactions if both drugs must be used together.
- captopril
captopril, allopurinol. Mechanism: unknown. Avoid or Use Alternate Drug. Risk of anaphylaxis, Stevens Johnson syndrome.
captopril increases toxicity of allopurinol by Mechanism: unspecified interaction mechanism. Avoid or Use Alternate Drug. May increase risk for allergic or hypersensitivity reactions to allopurinol Monitor for symptoms of hypersensitivty reactions if both drugs must be used together. - didanosine
allopurinol increases levels of didanosine by unknown mechanism. Contraindicated.
- enalapril
enalapril, allopurinol. Mechanism: unknown. Avoid or Use Alternate Drug. Risk of anaphylaxis, Stevens Johnson syndrome.
- perindopril
perindopril, allopurinol. Mechanism: unknown. Avoid or Use Alternate Drug. Risk of anaphylaxis, Stevens Johnson syndrome.
- pexidartinib
allopurinol and pexidartinib both increase Other (see comment). Avoid or Use Alternate Drug. Pexidartinib can cause hepatotoxicity. Avoid coadministration of pexidartinib with other products know to cause hepatoxicity.
- pretomanid
allopurinol, pretomanid. Either increases toxicity of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Pretomanid regimen associated with hepatotoxicity. Avoid alcohol and hepatotoxic agents, including herbal supplements and drugs other than bedaquiline and linezolid.
- protamine
allopurinol increases effects of protamine by decreasing metabolism. Avoid or Use Alternate Drug.
- ropeginterferon alfa 2b
ropeginterferon alfa 2b, allopurinol. Either increases toxicity of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Myelosuppressive agents can produce additive myelosuppression. Avoid use and monitor patients receiving the combination for effects of excessive myelosuppression.
- theophylline
allopurinol increases levels of theophylline by decreasing metabolism. Avoid or Use Alternate Drug.
- warfarin
allopurinol increases effects of warfarin by anticoagulation. Avoid or Use Alternate Drug.
Monitor Closely (15)
- acalabrutinib
acalabrutinib, allopurinol. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration may increase risk of myelosuppressive effects.
- aluminum hydroxide
aluminum hydroxide decreases levels of allopurinol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.
- amoxicillin
allopurinol decreases toxicity of amoxicillin by Other (see comment). Use Caution/Monitor. Comment: Allopurinol may increase potential for allergic or hypersensitivity reactions to amoxicillin.
- calcium carbonate
calcium carbonate decreases levels of allopurinol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.
- cyclophosphamide
allopurinol increases toxicity of cyclophosphamide by decreasing metabolism. Use Caution/Monitor.
- dichlorphenamide
dichlorphenamide and allopurinol both decrease serum potassium. Use Caution/Monitor.
dichlorphenamide, allopurinol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Both drugs can cause metabolic acidosis. - ethambutol
ethambutol decreases effects of allopurinol by Other (see comment). Use Caution/Monitor. Comment: Hyperuricemia reported with ethambutol and precipitation of gout reported; uric acid lowering agents may be require dosage adjustment.
- hydroxyurea
allopurinol, hydroxyurea. Other (see comment). Use Caution/Monitor. Comment: Combination may increase risk of myelosuppression.
- mercaptopurine
allopurinol increases levels of mercaptopurine by decreasing metabolism. Use Caution/Monitor. Potential for increased myelosuppression.
- methotrexate
allopurinol decreases effects of methotrexate by Other (see comment). Use Caution/Monitor. Comment: Combination may increase risk of myelosuppression.
- mipomersen
mipomersen, allopurinol. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Both drugs have potential to increase hepatic enzymes; monitor LFTs.
- sodium bicarbonate
sodium bicarbonate decreases levels of allopurinol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.
- sodium citrate/citric acid
sodium citrate/citric acid decreases levels of allopurinol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.
- thioguanine
allopurinol, thioguanine. unknown mechanism. Use Caution/Monitor. Potential for increased myelosuppression.
- valoctocogene roxaparvovec
allopurinol and valoctocogene roxaparvovec both increase Other (see comment). Use Caution/Monitor. Medications that may cause hepatotoxicity when combined with valoctogene roxaparvovec may potentiate the risk of elevated liver enzymes. Closely monitor these medications and consider alternative medications in case of potential drug interactions.
Minor (3)
- ampicillin
ampicillin, allopurinol. Mechanism: unknown. Minor/Significance Unknown. Increased incidence of rash.
- cyclosporine
allopurinol increases levels of cyclosporine by unknown mechanism. Minor/Significance Unknown.
- tacrolimus
allopurinol increases levels of tacrolimus by unknown mechanism. Minor/Significance Unknown.
Adverse Effects
1-10%
Rash (1.5%)
Nausea (1.3%)
Renal failure (1.2%)
Vomiting (1.2%)
Frequency Not Defined
Amblyopia
Arthralgias
Blood dyscrasias
Bronchospasm
Cardiovascular abnormalities
Cataracts
Confusion
Decrease in libido
Dizziness
Ecchymosis
Electrolyte abnormalities
Epistaxis
Foot drop
Hematuria
Hepatotoxicity
Hypotonia
Iritis
Kidney function abnormality
Macular retinitis
Malaise
Neuritis
Pharyngitis
Pruritus
Skin edema
Stevens-Johnson syndrome
Sweating
Tinnitus
Warnings
Contraindications
Patients with a history of severe reaction to any formulation of this drug
Cautions
Discontinue at first sign of allergic reactions (first sign of rash, vasculitis, or Stevens-Johnson syndrome, drug rash with eosinophilia and systemic symptoms (DRESS) and/or generalized vasculitis, irreversible hepatotoxicity)
The HLA-B*58:01 allele is a genetic marker for severe skin reactions indicative of hypersensitivity to allopurinol; patients who carry the HLA-B*58:01 allele are at a higher risk of allopurinol hypersensitivity syndrome (AHS); however, hypersensitivity reactions reported in patients who do not carry this allele; frequency of this allele is higher in individuals of African, Asian (e.g., Han Chinese, Korean, Thai), and Native Hawaiian/Pacific Islander ancestry; prior to starting therapy, consider testing for the HLA-B*58:01 allele in genetically at-risk populations; therapy not recommended in HLA-B*58:01 positive patients unless benefits clearly outweigh risks
Myelosuppression reported; use caution when administering other drugs known to cause myelosuppression; cytopenias have occurred as early as 6 weeks up to 6 years after initiation of therapy; concomitant use with cytotoxic drugs associated with myelosuppression may increase risk of myelosuppression; monitor blood counts more frequently when cytotoxic drugs are used concomitantly
Cases of reversible clinical hepatotoxicity have occurred in patients taking this medication, and in some patients, asymptomatic rises in serum alkaline phosphatase or serum transaminase have been observed; if anorexia, weight loss, or pruritus develop in patients on therapy, evaluate liver enzymes; in patients with pre-existing liver disease, monitor liver enzymes periodically; discontinue therapy in patients with elevated liver enzymes
Not for treatment of asymptomatic hyperuricemia
Risk of hypersensitivity increased in patients treated with angiotensin-converting emzyme (ACE) inhibitors
When taken with amoxicillin or ampicillin, may increase risk of skin rash
During concomitant treatment, reduce dosages of azathioprine and mercaptopurine to 25-33% of usual
Occurrence of hypersensitivity reactions may be increased in patients with renal impairment, especially in patients who are receiving thiazide diuretics; reduce dose in patients with impaired renal function
Risk of hypersensitivity may increase with concomitant administration of thiazides
Maintain fluid intake necessary to yield urine output of at least 2 L/day in adults
Gout flares
- Gout flares have been reported during initiation of treatment, even when normal or subnormal serum uric acid levels have been attained due to mobilization of urates from tissue deposits
- Even with adequate therapy, it may require several months to deplete the uric acid pool sufficiently to achieve control of the flares; the flares typically become shorter and less severe after several months of therapy
- In order to prevent gout flares when treatment initiated, concurrent prophylactic treatment with colchicine or an anti-inflammatory agent is recommended
- Advise patients to continue therapy and prophylactic treatment even if gout flares occur, as it may take months to achieve control of gout flares
Nephrotoxicity
- Treatment may result in acute kidney injury due to formation of xanthine calculi or due to precipitation of urates in patients receiving concomitant uricosuric agents
- Patients with pre-existing kidney disease, including chronic kidney disease or history of kidney stones, may be at increased risk for worsening of kidney function or acute kidney injury due to xanthine calculi while receiving treatment
- In patients receiving therapy for the management of gout or the management of recurrent calcium oxalate calculi, monitor kidney function frequently during the early stages of allopurinol administration
- Maintain fluid intake sufficient to yield a urinary output of at least 2 liters per day of neutral or, preferably, slightly alkaline urine to avoid the possibility of formation of xanthine calculi and help prevent renal precipitation of urates in patients receiving concomitant uricosuric agents
- In patients receiving this medication for the management of tumor lysis syndrome, monitor kidney function at least daily during the early stages of allopurinol administration
- Maintain fluid intake sufficient to yield a urinary output of at least 2 liters per day in adults and at least 2 liters/m2/day (or at least 100 mL/m2/hour) in pediatric patients
Pregnancy & Lactation
Pregnancy
Available limited published data on allopurinol use in pregnant women do not demonstrate a clear pattern or increase in frequency of adverse developmental outcomes. Among approximately 50 pregnancies described in published literature, 2 infants with major congenital malformations have been reported with following maternal allopurinol exposure. Advise pregnant women of the potential risk to a fetus
Animal data
- Based on findings in animals, this drug may cause fetal harm when administered to a pregnant woman; adverse developmental outcomes described in exposed animals; this drug and its metabolite oxypurinol shown to cross placenta following administration of maternal allopurinol
- Reproductive studies performed in rats and rabbits at doses up to twenty times usual human dose (5 mg/kg per day) concluded that there was no impaired fertility or harm to fetus due to allopurinol; there is a published report of a study in pregnant mice given 50 or 100 mg/kg allopurinol intraperitoneally on gestation days 10 or 13; there were increased numbers of dead fetuses in dams given 100 mg/kg allopurinol but not in those given 50 mg/kg
- There were increased numbers of external malformations in fetuses at both doses of allopurinol on gestation day 10 and increased numbers of skeletal malformations in fetuses at both doses on gestation day 13; it cannot be determined whether this represented a fetal effect or an effect secondary to maternal toxicity; there are, however, no adequate or well controlled studies in pregnant women; because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed
Lactation
Allopurinol and oxypurinol are present in human milk; based on information from a single case report, allopurinol and its active metabolite, oxypurinol, were detected in the milk of a mother at five weeks postpartum at an estimated relative infant dose of 0.14 and 0.2 mg/kg of allopurinol and between 7.2 to 8 mg/kg of oxypurinol daily
There was no report of effects of allopurinol on the breastfed infant or on milk production; because of potential for serious adverse reactions in a breastfed child, advise women not to breastfeed during treatments with this drug and for one week after last dose
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Xanthine oxidase inhibitor; inhibits conversion of hypoxanthine to xanthine to uric acid; decreases production of uric acid without disrupting synthesis of vital purines
Pharmacokinetics
Bioavailability: 49-53%
Onset: 2-3 days
Peak plasma time: 0.5-2 hr
Time to peak effect: 7-14 days
Distribution
Protein bound: <1%
Vd: 1.6-2.4 L/kg
Metabolism
Metabolized in liver
Metabolites: Oxypurinol (active), allopurinol riboside (activity unknown)
Elimination
Half-life: Parent drug, 1-3 hr; active metabolite, 15-20 hr
Dialyzable: Yes (both hemodialysis and peritoneal dialysis)
Renal clearance: 30 mL/min
Total body clearance: 16 mL/min/kg
Excretion: Urine (80%), feces (10-20%)
Administration
IV Compatibilities
Y-site (partial list): Acyclovir, calcium gluconate, cefazolin, ceftriaxone, carboplatin, cisplatin, cyclophosphamide, dactinomycin, doxorubicin liposomal, fluorouracil, ifosfamide, mesna, metronidazole, mitoxantrone, morphine sulfate, potassium chloride, thiotepa, vancomycin
IV Incompatibities
Y-site: Amikacin, amphotericin B, carmustine, cefotaxime, chlorpromazine, cimetidine, clindamycin, cytarabine, dacarbazine, daunorubicin, diphenhydramine, doxorubicin, doxycycline, droperidol, floxuridine, gentamicin, haloperidol, hydroxyzine, idarubicin, imipenem-cilastatin, mechlorethamine, meperidine, methylprednisolone sodium succinate, metoclopramide, minocycline, nalbuphine, netilmicin, ondansetron, prochlorperazine, promethazine, sodium bicarbonate, streptozocin, tobramycin, vinorelbine
IV Preparation
Reconstitute with 25 mL SWI
Dilute to desired concentration with NS or D5W; do not use sodium bicarbonate-containing solutions; final concentration of ≤6 mg/mL is recommended
Store solution at 20-25°C (do not refrigerate), and use within 10 hours after reconstitution
IV Administration
In both adults and children, daily dose can be given as single infusion or in equally divided infusions q6hr, q8hr, or q12hr
Whenever possible, administration should be initiated 1-2 days before start of chemotherapy known to cause tumor cell lysis (including adrenocorticosteroids)
Images
| BRAND | FORM. | UNIT PRICE | PILL IMAGE |
|---|---|---|---|
| allopurinol oral - | 300 mg tablet |  | |
| allopurinol oral - | 100 mg tablet |  | |
| allopurinol oral - | 300 mg tablet |  | |
| allopurinol oral - | 100 mg tablet |  | |
| allopurinol oral - | 300 mg tablet |  | |
| allopurinol oral - | 300 mg tablet |  | |
| allopurinol oral - | 300 mg tablet |  | |
| allopurinol oral - | 100 mg tablet |  | |
| allopurinol oral - | 300 mg tablet |  | |
| allopurinol oral - | 100 mg tablet |  | |
| allopurinol oral - | 100 mg tablet |  | |
| allopurinol oral - | 100 mg tablet |  | |
| allopurinol oral - | 300 mg tablet |  | |
| allopurinol oral - | 300 mg tablet |  | |
| allopurinol oral - | 100 mg tablet |  | |
| allopurinol oral - | 100 mg tablet |  | |
| allopurinol oral - | 300 mg tablet |  | |
| allopurinol oral - | 100 mg tablet |  | |
| allopurinol oral - | 300 mg tablet |  | |
| allopurinol oral - | 100 mg tablet |  | |
| Zyloprim oral - | 100 mg tablet |  | |
| Zyloprim oral - | 300 mg tablet |  |
Copyright © 2010 First DataBank, Inc.
Patient Handout
allopurinol oral
ALLOPURINOL - ORAL
(AL-oh-PURE-i-nol)
COMMON BRAND NAME(S): Zyloprim
USES: Allopurinol is used to treat gout and certain types of kidney stones. It is also used to prevent increased uric acid levels in patients receiving cancer chemotherapy. These patients can have increased uric acid levels due to release of uric acid from the dying cancer cells. Allopurinol works by reducing the amount of uric acid made by the body. Increased uric acid levels can cause gout and kidney problems.
HOW TO USE: Take this medication by mouth as directed by your doctor, usually once daily. Take this medication after a meal to reduce stomach upset. If your dose is more than 300 milligrams a day, you will need to take several smaller doses during the day to get this amount (ask your doctor for directions).It is best to drink a full glass of water with each dose and at least 8 more glasses (8 ounces each) of fluid a day. If your doctor has directed you to drink less fluid for other medical reasons, consult your doctor for further instructions. Your doctor may also instruct you on how to decrease acid in your urine (such as avoiding large amounts of ascorbic acid/vitamin C).Dosage is based on your medical condition and response to treatment. Use this medication regularly to get the most benefit from it. To help you remember, take it at the same time(s) each day.For the treatment of gout, it may take up to several weeks for this medicine to have an effect. You may have more gout attacks for several months after starting this medicine while the body removes extra uric acid. Allopurinol is not a pain reliever. To relieve pain from gout, continue to take your prescribed medicines for gout attacks (such as colchicine, ibuprofen, indomethacin) as directed by your doctor.Tell your doctor if your condition lasts or gets worse.
SIDE EFFECTS: Stomach upset, nausea, diarrhea, or drowsiness may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor right away if you have any serious side effects, including: numbness/tingling of arms/legs, easy bleeding/bruising, unusual tiredness, signs of kidney problems (such as change in the amount of urine, painful/bloody urination), signs of liver disease (such as nausea/vomiting that doesn't stop, loss of appetite, stomach/abdominal pain, yellowing eyes/skin, dark urine), unusual weight loss, eye pain, vision changes.Allopurinol may rarely cause very serious (possibly fatal) skin reactions. Some people in certain ethnic groups (such as people of African, Asian, or Native Hawaiian/Pacific Islander descent) are at greater risk. Your doctor may order a blood test to measure your risk before you start this medication. If the blood test shows you are at greater risk, your doctor should discuss the risks and benefits of allopurinol and other treatment choices with you. Get medical help right away if you develop any symptoms of a serious skin reaction, including: skin rash/blisters/peeling, itching, or swelling. Ask your doctor or pharmacist for more details.A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: fever, swollen lymph nodes, rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
PRECAUTIONS: Before taking allopurinol, tell your doctor or pharmacist if you are allergic to it; or if you have had a severe reaction to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: liver disease, kidney disease, diabetes, high blood pressure (hypertension), unusual diets (such as fasting).This drug may make you drowsy. Alcohol or marijuana (cannabis) can make you more drowsy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Alcohol may also decrease the effectiveness of this drug. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.Allopurinol passes into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breastfeeding.
DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (such as prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.Some products that may interact with this drug are: "blood thinners" (such as warfarin), capecitabine, didanosine.
OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.
NOTES: Do not share this medication with others.Lab and/or medical tests (such as uric acid blood levels, liver/kidney function, complete blood count) may be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.If you are taking allopurinol to treat kidney stones, you may benefit from a special diet. Consult your doctor for more details.
MISSED DOSE: If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.
STORAGE: Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
Information last revised October 2023. Copyright(c) 2023 First Databank, Inc.
IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
Formulary
Adding plans allows you to compare formulary status to other drugs in the same class.
To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.
Adding plans allows you to:
- View the formulary and any restrictions for each plan.
- Manage and view all your plans together – even plans in different states.
- Compare formulary status to other drugs in the same class.
- Access your plan list on any device – mobile or desktop.
