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allopurinol
Apo-Allopurinol†, Capurate‡, Lopurin, Purinol†, Zyloprim, Zyloric§

Pregnancy Risk Category C

How supplied
Tablets (scored):
100 mg, 200 mg†, 300 mg
Capsules:
100 mg‡, 300 mg‡
Injection:
500 mg/30 ml vial

Action
Reduces uric acid production by inhibiting biochemical reactions preceding its formation.

Indications & dosage
Gout, primary or secondary to hyperuricemia; secondary to diseases such as acute or chronic leukemia, polycythemia vera, multiple myeloma, psoriasis--

Dosage varies with severity of disease; can be given as single dose or divided, but doses above 300 mg should be divided.
Adults:
mild gout, 200 to 300 mg P.O. daily; severe gout with large tophi, 400 to 600 mg P.O. daily. Same dosage for maintenance in secondary hyperuricemia. Maximum dose is 800 mg/day. Or, give 200 to 400 mg/m2/day I.V. as a single infusion or equally divided dose q 6, 8, or 12 hours.
Children:
initially 200 mg/m2/day I.V. as single infusion or equally divided dose q 6, 8, or 12 hours.
Hyperuricemia secondary to malignancies
--
Children under age 6:
50 mg P.O. t.i.d.
Children ages 6 to 10:
300 mg P.O. daily or divided t.i.d.
Prevention of acute gouty attacks--

Adults:
100 mg P.O. daily; increase at weekly intervals by 100 mg without exceeding maximum dose (800 mg), until serum uric acid falls to 6 mg/dl or less.
Prevention of uric acid nephropathy during cancer chemotherapy--

Adults:
600 to 800 mg P.O. daily for 2 to 3 days, with high fluid intake.
Recurrent calcium oxalate calculi--

Adults:
200 to 300 mg P.O. daily in single or divided doses.
Adjust-a-dose:
For renally impaired patients, 200 mg P.O. or I.V. daily if creatinine clearance is 10 to 20 ml/minute; 100 mg P.O. or I.V. daily if below 10 ml/minute; and 100 mg P.O. or I.V. q 48 hours if below 3 ml/minute.

Adverse reactions
CNS:
drowsiness, headache, paresthesia, peripheral neuropathy, neuritis.
CV:
hypersensitivity vasculitis, necrotizing angiitis.
EENT:
epistaxis.
GI:
nausea, vomiting, diarrhea, abdominal pain, gastritis, taste loss or perversion, dyspepsia.
GU: renal failure,
uremia.
Hematologic:
agranulocytosis, anemia, aplastic anemia, thrombocytopenia, leukopenia, leukocytosis, eosinophilia.
Hepatic:
hepatitis, hepatic necrosis, hepatomegaly, cholestatic jaundice, increased alkaline phosphatase, AST, and ALT levels.
Musculoskeletal:
arthralgia, myopathy.
Skin:
rash; exfoliative, urticarial, and purpuric lesions; erythema multiforme; severe furunculosis of nose; ichthyosis; alopecia; toxic epidermal necrolysis.
Other:
ecchymoses, fever, chills.

Interactions
Drug-drug.
Amoxicillin, ampicillin, bacampicillin: increased possibility of rash. Avoid concomitant use.
Anticoagulants except warfarin:
potentiation of anticoagulant effect. Dosage adjustments may be needed.
Antineoplastics:
increased potential for bone marrow suppression. Monitor patient carefully.
Chlorpropamide:
possible increased hypoglycemic effect. Avoid concomitant use.
Diazoxide, diuretics, mecamylamine, pyrazinamide:
increased serum uric acid level. Adjust dosage of allopurinol.
Ethacrynic acid, thiazide diuretics:
increased risk of allopurinol toxicity. Reduce dosage of allopurinol, and closely monitor renal function.
Uricosurics:
additive effect. May enhance therapy.
Urine-acidifying drugs (ammonium chloride, ascorbic acid, potassium or sodium phosphate):
may increase possibility of kidney stone formation. Monitor patient carefully.
Xanthines:
increased serum theophylline levels. Adjust dosage of theophylline, as needed.
Drug-lifestyle.
Alcohol use: increased serum uric acid levels. Avoid alcohol use.

Effects on diagnostic tests
None reported.

Contraindications
Contraindicated in patients with hypersensitivity to drug and in those with idiopathic hemochromatosis.

Nursing considerations


Alert:
Don't confuse Zyloprim with ZORprin.

I.V. administration

Patient teaching

*Liquid contains alcohol. **May contain tartrazine.  †Canada  ‡Australia  §U.K.  OTCOver the counter
Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE-THREATENING

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