Allopurinol Dosage

Medically reviewed by Drugs.com. Last updated on Mar 10, 2025.

Usual Adult Dose for Gout

Dose will vary with the severity of the disease:
Initial dose: 100 mg orally once a day

• Increase in increments of 100 mg weekly until a serum uric level of 6 mg/dL or less is attained.

Mild Gout: Average maintenance dose: 200 to 300 mg orally once a day
Moderately Severe Tophaceous Gout: Average maintenance dose: 400 to 600 mg orally once a day or in divided doses
Minimal Effective Dose: 100 to 200 mg per day
Maximum Dose: 800 mg per day

Comments:

• Oral doses greater than 300 mg/day should be given in divided doses, preferably after meals to minimize gastric irritation.
• A gradual dose titration is recommended to reduce the possibility of acute gouty attacks.
• Normal serum urate levels are usually achieved in 1 to 3 weeks.
• Before starting therapy in patients with gout, it is recommended to assess the serum uric acid level, complete blood count, chemistry panel, liver function tests (serum ALT, AST, alkaline phosphatase, and total bilirubin), and kidney function tests (serum creatinine and estimated glomerular filtration rate).

Use: For the management of patients with signs and symptoms of primary or secondary gout (acute attacks, tophi, joint destruction, uric acid lithiasis, and/or nephropathy)

Usual Adult Dose for Hyperuricemia Secondary to Chemotherapy

Parenteral:
200 to 400 mg/m2/day IV as a single infusion or in equally divided infusions at 6, 8, or 12 hour intervals
Maximum dose: 600 mg/day

Oral:
Initial dose: 300 to 800 mg orally once a day or in divided doses
Maintenance: Adjust dose as needed based on serum uric acid levels
Maximum dose: 800 mg per day

Comments:

• When possible, therapy should be initiated 24 to 48 hours before the start of chemotherapy; treatment should be discontinued when the potential for overproduction of uric acid is no longer present.
• Oral doses greater than 300 mg/day should be given in divided doses, preferably after meals to minimize gastric irritation.
• The dose to lower serum uric acid to normal or near-normal varies with the severity of the disease; the above dosing represents suggested doses; serum uric acid levels should serve as an index.
• Fluid intake should be sufficient to maintain a daily urinary output of at least 2 L; neutral or preferably slightly alkaline urine is desirable.

Use: For the management of patients with leukemia, lymphoma, and malignancies who are receiving cancer therapy which causes elevations of serum and urinary uric acid levels; IV therapy is available for patients who cannot tolerate oral therapy

Usual Adult Dose for Calcium Oxalate Calculi with Hyperuricosuria

200 to 300 mg orally once a day or in divided doses

Comments:

• Carefully assess risk versus benefit when initiating therapy and periodically thereafter.
• Dose adjustments should be based on control of hyperuricosuria based on 24-hour urinary urate determinations.
• Clinical experience suggests these patients may benefit from dietary changes in addition to drug therapy.

Use: For the management recurrent calcium oxalate calculi in patients whose daily uric acid excretion exceeds 800 mg/day in males or 750 mg/day in females

Usual Pediatric Dose for Hyperuricemia Secondary to Chemotherapy

Parenteral:
Initial dose: 200 mg/m2/day IV as a single infusion or in equally divided infusions at 6, 8, or 12 hours intervals
Maximum dose: 400 mg/day

Oral:
100 mg/m2 orally every 8 hours to 12 hours
Maximum dose: 800 mg per day

Comments:

• Oral doses greater than 300 mg should be administered in divided doses.
• In patients with body surface area less than 0.5 m2, consider using an alternative allopurinol formulation.
• When possible, therapy should be initiated 24 to 48 hours before the start of chemotherapy; treatment should be discontinued when the potential for overproduction of uric acid is no longer present.
• The dose to lower serum uric acid to normal or near-normal varies with the severity of the disease; the above dosing represents suggested doses in children; serum uric acid levels should serve as an index.
• Fluid intake should be sufficient to maintain a daily urinary output of at least 2 L; neutral or preferably slightly alkaline urine is desirable.

Use: For the management of patients with leukemia, lymphoma, and malignancies who are receiving cancer therapy which causes elevations of serum and urinary uric acid levels; IV therapy is available for patients who cannot tolerate oral therapy

Usual Pediatric Dose for Lesch-Nyhan Syndrome

Parenteral:
Initial dose: 200 mg/m2/day IV as a single infusion or in equally divided infusions at 6, 8, or 12 hours intervals
Maximum dose: 400 mg/day

Oral:
100 mg/m2 orally every 8 hours to 12 hours
Maximum dose: 800 mg per day

Comments:

• Oral doses greater than 300 mg should be administered in divided doses.
• In patients with body surface area less than 0.5 m2, consider using an alternative allopurinol formulation.
• When possible, therapy should be initiated 24 to 48 hours before the start of chemotherapy; treatment should be discontinued when the potential for overproduction of uric acid is no longer present.
• The dose to lower serum uric acid to normal or near-normal varies with the severity of the disease; the above dosing represents suggested doses in children; serum uric acid levels should serve as an index.
• Fluid intake should be sufficient to maintain a daily urinary output of at least 2 L; neutral or preferably slightly alkaline urine is desirable.

Use: For the management of patients with leukemia, lymphoma, and malignancies who are receiving cancer therapy which causes elevations of serum and urinary uric acid levels; IV therapy is available for patients who cannot tolerate oral therapy

Renal Dose Adjustments

Patients with Gout:
Oral - Adults:
Initial dose:

• Estimated glomerular filtration rate (eGFR) greater than 60 mL/min: No adjustment recommended
• Estimated GFR 30 to less than 60 mL/min: 50 mg orally once a day
• Estimated GFR 15 to less than 30 mL/min: 50 mg orally every other day
• Estimated GFR 15 to less than 5 mL/min: 50 mg orally every 2 weeks
• Estimated GFR less than 5 mL/min: 50 mg orally once a week
• Manufacturer make no recommendation regarding the maximum dosage that should be used in patients with various levels of renal impairment.

For the Management of Hyperuricemia Associated with Cancer Therapy:
Parenteral - Adults:
CrCl 10 to 20 mL/min: 200 mg IV/orally once a day
CrCl less than 10 mL/min: 100 mg IV/orally once a day

Oral - Adults:

• Estimated GFR 20 to less than 60 mL/min: No adjustment recommended
• Estimated GFR 10 to less than 20 mL/min: 200 mg orally once a day
• Estimated GFR less than 10 mL/min: 100 mg orally once a day

Pediatrics: This drug has not been studied in pediatric patients with severe renal impairment or on dialysis. Consider the risks and potential benefits before initiating treatment. No dosage adjustments provided.

Patients with Recurrent Calcium Oxalate Calculi: Data not available

Liver Dose Adjustments

Data not available

If anorexia, weight loss, or pruritus develops, an evaluation of liver function tests should be part of diagnostic workup.

Dose Adjustments

Patients receiving Concomitant Colchicine and/or NSAIDs:

• Continue colchicine and/or NSAID therapy until serum uric acid level has been normalized and patient has been free from acute gouty attacks for several months.

Switching from a Uricosuric Agent:

• Gradually reduce the dose of the uricosuric agent while increasing the allopurinol dose to a dose that maintains a normal serum uric acid level; this may take several weeks.

• Concomitant administration of allopurinol 300 to 600 mg per day with mercaptopurine or azathioprine will require dose reduction of mercaptopurine or azathioprine to one-third or one-fourth of the usual dose.

Therapeutic drug monitoring:

• Dose adjustments should be based on serum uric acid concentrations and urinary uric acid levels.
• Because estimation of uric acid can be difficult, reliance on single serum uric acid determinations is not recommended.

Serum Uric Acid Levels (upper limit of normal):

• Men and premenopausal women: 7 mg/dL
• Postmenopausal women: 6 mg/dL

Precautions

CONTRAINDICATIONS:

• In patients with a history of severe reaction to any formulation of this drug
• Hypersensitivity to the active component or any of the ingredients

Safety and efficacy have not been established in patients younger than 18 years for primary or secondary gout, recurrent calcium oxalate calculi and with rare inborn errors of purine metabolism.

Consult WARNINGS section for additional precautions.

Dialysis

This drug is dialyzable; consider dosing after each dialysis session.

For the Management of Hyperuricemia Associated with Cancer Therapy:
Adults:
Hemodialysis: 50 mg IV every 12 hours or 100 mg IV every 24 hours
Peritoneal dialysis: 50 mg IV every 12 hours or 100 mg IV every 24 hours
Pediatrics: Data not available

Other Comments

Administration advice:

• Dose adjustments may be required in older adults; however, no specific guidelines have been suggested. Caution recommended.
• Maintain fluid intake sufficient to yield a daily urinary output of at least 2 L; neutral or slightly alkaline urine is desirable.
• Inspect the reconstituted and diluted solution for discoloration and particulate matter.
• Do not use if the reconstituted and diluted solution contains particulate matter or discoloration is present.

Oral:

• Take orally after meals to minimize gastric irritation.
• Oral doses greater than 300 mg should be administered in divided doses.
• Missed dose: Do not double dose at next scheduled time.

Parenteral:

• Administer as a single IV infusion or in equally divided infusions at 6, 8, or 12 hour intervals.
• Final concentration should not exceed 6 mg/mL; rate of infusion depends on the volume of infusate.

Reconstitution/preparation techniques:

• Reconstitute 500 mg vial with 25 mL of sterile water for injection.
• Prior to administration, dilute to a final concentration of no greater than 6 mg/mL with 0.9% Sodium Chloride or 5% Dextrose; sodium bicarbonate-containing solutions should not be used.
• IV administration should begin within 10 hours of reconstitution.

Storage requirements:

• Store at 20C to 25C (68F to 77F) with excursions permitted to 15C to 30C (59F to 86F).
• Store tablets in a dry place protected from light.
• Diluted solution can be stored at 20C to 25C (68F to 77F) if not used immediately; do not refrigerate the reconstituted and/or diluted product.

IV compatibility:

• The following drugs are physically incompatible in solution with allopurinol sodium: amikacin sulfate, amphotericin B, carmustine, cefotaxime sodium, chlorpromazine hydrochloride, cimetidine hydrochloride, clindamycin phosphate, cytarabine, dacarbazine, daunorubicin hydrochloride, diphenhydramine hydrochloride, doxorubicin hydrochloride, doxycycline hyclate, droperidol, floxuridine, gentamicin sulfate, haloperidol lactate, hydroxyzine hydrochloride, idarubicin hydrochloride, imipenem-cilastatin sodium, mechlorethamine hydrochloride, meperidine hydrochloride, metoclopramide hydrochloride, methylprednisolone sodium succinate, minocycline hydrochloride, nalbuphine hydrochloride, netilmicin sulfate, ondansetron hydrochloride, prochlorperazine edisylate, promethazine hydrochloride, sodium bicarbonate, streptozocin, tobramycin sulfate, and vinorelbine tartrate

General:

• This drug is not recommended for the treatment of asymptomatic hyperuricemia.
• Dosage for maintaining serum uric acid within the normal range is best determined by using the serum uric acid level as an index.
• Except for use for hyperuricemia secondary to malignancy or for certain rare inborn errors of purine metabolism, this drug is rarely indicated in children.
• Gout flares may occur after initiating this drug due to changing serum uric acid levels, which should be managed concurrently, as appropriate for the individual patient.

Monitoring:
Hepatic: Liver function periodically during the early stages of therapy (serum ALT, AST, alkaline phosphatase, and total bilirubin)
Hematologic: Serum uric acid levels (at least daily), complete blood cell counts (more frequently when cytotoxic drugs are used concomitantly), differential blood counts
Others: Chemistry panel
Renal: Kidney function (serum creatinine and eGFR) at least daily during initial stages of treatment, hypoglycemia

Patient advice:

• Read the US FDA-approved patient labeling.
• Gout flares may be experienced with this drug, continue treatment.
• Increase fluid intake during therapy to prevent kidney stones.
• Discontinue this drug immediately if you develop any type of rash and seek medical attention.
• Stay well hydrated while taking this drug.
• Report any signs and symptoms of infection, fever, bleeding, shortness of breath, or significant fatigue to your healthcare provider.
• Drowsiness may occur be cautious when engaging in activities where alertness is mandatory.
• Female patients taking this drug should notify their healthcare provider if they become pregnant or intend to become pregnant during therapy.
• Inform your physician about all the current medication.

See also:

Further information

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