Drug Name
Generic Name: allopurinol
Brand Name: Aloprim, Apo-Allopurinol (CAN), Purinol (CAN), Zyloprim
Classification: Antigout drug
Pregnancy Category C
Dosages
ADULTS
- Gout and hyperuricemia: 100–800 mg/day PO in divided doses, depending on the severity of the disease (200–300 mg/day is usual dose).
- Maintenance: Establish dose that maintains serum uric acid levels within normal limits.
- Prevention of acute gouty attacks: 100 mg/day PO; increase the dose by 100 mg at weekly intervals until uric acid levels are < 6 mg/dL.
- Prevention of uric acid nephropathy in certain malignancies: 600–800 mg/day PO for 2–3 days with a high fluid intake; maintenance dose should then be established as above.
- Recurrent calcium oxalate stones: 200–300 mg/day PO; adjust dose based on 24-hr urinary urate determinations.
- Parenteral: 200–400 mg/m2/day IV to maximum of 600 mg/day as continuous infusion or at 6, 8, 12 hr intervals.
PEDIATRIC PATIENTS
- Secondary hyperuricemia associated with various malignancies:
- 6–10 yr: 300 mg/day PO.
- < 6 yr: 150 mg/day; adjust dosage after 48 hr of treatment based on serum uric acid levels.
- Parenteral: 200 mg/m2/day IV as continuous infusion or at 6-, 8-, 12-hr intervals.
Therapeutic actions
- Inhibits the enzyme responsible for the conversion of purines to uric acid, thus reducing the production of uric acid with a decrease in serum and sometimes in urinary uric acid levels, relieving the signs and symptoms of gout
Indications
- Management of the signs and symptoms of primary and secondary gout
- Management of patients with malignancies that result in elevations of serum and urinary uric acid
- Management of patients with recurrent calcium oxalate calculi whose daily uric acid excretion exceeds 800 mg/day (males) or 750 mg/day (females)
- Orphan drug use: Treatment of Chagas’ disease; cutaneous and visceral leishmaniasis
- Unlabeled uses: Amelioration of granulocyte suppression with 5-FU; as a mouthwash to prevent 5-FU-induced stomatitis
Adverse effects
- CNS: Headache, drowsiness, peripheral neuropathy, neuritis, paresthesias
- Dermatologic: Rashes—maculopapular, scaly or exfoliative—sometimes fatal
- GI: Nausea, vomiting, diarrhea, abdominal pain, gastritis, hepatomegaly, hyperbilirubinemia, cholestatic jaundice
- GU: Exacerbation of gout and renal calculi, renal failure
- Hematologic: Anemia, leukopenia, agranulocytosis, thrombocytopenia, aplastic anemia, bone marrow depression
Contraindications
- Contraindicated with allergy to allopurinol, blood dyscrasias.
- Use cautiously with liver disease, renal failure, lactation, pregnancy.
Nursing considerations
Assessment
- History: Allergy to allopurinol, blood dyscrasias, liver disease, renal failure, lactation
- Physical: Skin lesions, color; orientation, reflexes; liver evaluation, normal urinary output; normal output; CBC, LFTs, renal function tests, urinalysis
Interventions
- Administer drug following meals.
- Encourage patient to drink 2.5 to 3 L/day to decrease the risk of renal stone development.
- Check urine alkalinity—urates crystallize in acid urine; sodium bicarbonate or potassium citrate may be ordered to alkalinize urine.
- WARNING: Discontinue drug at first sign of skin rash; severe to fatal skin reactions have occurred.
- Arrange for regular medical follow-up and blood tests.
Teaching points
- Take the drug after meals.
- Avoid over-the-counter medications. Many of these preparations contain vitamin C or other agents that might increase the likelihood of kidney stone formation. If you need an over-the-counter preparation, check with your health care provider.
- You may experience these side effects: Exacerbation of gouty attack or renal stones (drink 2.5–3 liters of fluids per day while on this drug); nausea, vomiting, loss of appetite (takes after meals or eat frequent small meals); drowsiness (use caution while driving or performing hazardous tasks).
- Report unusual bleeding or bruising; fever, chills; gout attack; numbness or tingling; flank pain, skin rash.