• PO: Prevention of attack of gouty arthritis and nephropathy.
• PO, IV: Treatment of secondary hyperuricemia, which may occur during treatment of tumors or leukemias.

Contraindicated in:

• Hypersensitivity
• Presence of HLA-B*58:01 allele (↑ risk of hypersensitivity reactions)
• Lactation: Lactation.

Use Cautiously in:

• Acute attacks of gout
• Renal impairment (dose ↓ required if CCr <20 mL/min)
• Dehydration (adequate hydration necessary)
• OB: Safety not established in pregnancy
• Geri: Begin at lower end of dosage range in older adults.

CV: bradycardia, flushing, heart failure (reported with IV administration), hypertension, hypotension.

Derm: rash (discontinue drug at first sign of rash), DRUG REACTION WITH EOSINOPHILIA AND SYSTEMIC SYMPTOMS (DRESS), STEVENS-JOHNSON SYNDROME, TOXIC EPIDERMAL NECROLYSIS, urticaria.

GI: diarrhea, hepatitis, nausea, vomiting.

GU: hematuria, renal failure.

Hemat: bone marrow depression.

Neuro: drowsiness.
Misc: HYPERSENSITIVITY REACTIONS.

Drug-Drug:

• Use with mercaptopurine and azathioprine↑ bone marrow depressant properties — doses of these drugs should be ↓.
• Use with ampicillin or amoxicillin↑ risk of rash.
• Use with oral hypoglycemic agents and warfarin↑ effects of these drugs.
• Use with thiazide diuretics or ACE inhibitors↑ risk of hypersensitivity reactions.
• Large doses of allopurinol may ↑ risk of theophylline toxicity.
• May ↑ cyclosporine levels.

(Generic available)

• Tablets: 100 mg; 200 mg; 300 mg;
• Powder for injection: 500 mg/vial;

Gout

• PO (Adults and Children >10 yr): Initially: 100 mg/day; ↑ at weekly intervals based on serum uric acid (not to exceed 800 mg/day). Doses >300 mg/day should be given in divided doses; Maintenance dose: 100–200 mg 2–3 times daily. Doses of 300 mg may be given as a single daily dose.

Secondary Hyperuricemia

• PO (Adults and Children >10 yr): 600–800 mg/day in 2–3 divided doses starting 1–2 days before chemotherapy or radiation.
• PO (Children 6–10 yr): 10 mg/kg/day in 2–3 divided doses (maximum 800 mg/day) or 300 mg daily in 2–3 divided doses.
• PO (Children <6 yr): 10 mg/kg/day in 2–3 divided doses (maximum 800 mg/day) or 150 mg daily in 3 divided doses.
• IV (Adults and Children >10 yr): 200–400 mg/m²/day (up to 600 mg/day) as a single daily dose or in divided doses every 8–24 hr.
• IV (Children <10 yr): 200 mg/m²/day initially as a single daily dose or in divided doses every 8–24 hr (maximum dose 600 mg/day).

Aloprim, Zyloprim

• Inhibits the production of uric acid by inhibiting the action of xanthine oxidase.

• Lowering of serum uric acid levels.

Therapeutic Classification: antigout agents, antihyperuricemics

Pharmacologic Classification: xanthine oxidase inhibitors

Absorption: Well absorbed (80%) following oral administration.

Distribution: Widely distributed in tissue and breast milk.

Protein Binding: <1%.

Metabolism/Excretion: Metabolized to oxypurinol, an active compound with a long half-life. 12% excreted unchanged, 76% excreted as oxypurinol.

Half-life: 1–3 hr (oxypurinol 18–30 hr).

(hypouricemic effect)

†Duration after discontinuation of allopurinol.

• Instruct patient to take allopurinol as directed. Take missed doses as soon as remembered. If dosing schedule is once daily, do not take if remembered the next day. If dosing schedule is more than once a day, take up to 300 mg for next dose.
• Instruct patient to continue taking allopurinol along with an NSAID or colchicine during an acute attack of gout. Allopurinol helps prevent, but does not relieve, acute gout attacks.
• Alkaline diet may be ordered. Urinary acidification with large doses of vitamin C or other acids may increase kidney stone formation (see Appendix M). Advise patient of need for increased fluid intake.
• May occasionally cause drowsiness. Caution patient to avoid driving or other activities requiring alertness until response to drug is known.
• Instruct patient to report skin rash, blood in urine, influenza symptoms (chills, fever, muscle aches and pains, nausea, or vomiting) or symptoms of DRESS to health care professional immediately; skin rash may indicate hypersensitivity.
• Advise patient that large amounts of alcohol increase uric acid concentrations and may decrease the effectiveness of allopurinol.
• Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected and to avoid breastfeeding during therapy and for 1 wk after last dose.
• Emphasize the importance of follow-up exams to monitor effectiveness and side effects.

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