Allopurinol (Agent for Gout)

Question 1

What is the brand name of allopurinol?

Answer 1

Zyloprim

Question 2

What are the available tablets strengths of allopurinol?

Answer 2

100 mg & 300 mg

Question 3

What is the available injection strengths of allopurinol?

Answer 3

500 mg and a 30 mL single dose vial

Question 4

What are the FDA approved indications of Zyloprim?`

Answer 4

Treatment of gout, prevention of uric acid nephropathy, prevention of flareup of acute gouty arthritis, secondary hyperuricemia, treatment of recurrent calcium oxalate stones

Question 5

What dose of allopurinol is used to treat gout?

Answer 5

200 mg to 300 mg per day for mild gout, or 400 mg to 600mg per day in divided doses for moderately severe tophaceous gout.

Question 6

What dose allopurinol is used for the prevention of uric acid nephropathy?

Answer 6

600 mg to 800 mg per day for 2 to 3 days given in divided doses with a high fluid intake

Question 7

What dose of allopurinol is used for the prevention of flareup gouty arthritis?

Answer 7

100 mg per day initially, followed by increase of 100 mg per week without exceeding recommended dosages until serum uric acid level is 6 mg/100mL or less

Question 8

What dose of allopurinol is used for the treatment a secondary hyperuricemia?

Answer 8

300 mg per day for children 6 to 10 years of age. Children under six years are usually given 150 mg per day

Question 9

What dose allopurinol is used to treat recurrent calcium oxalate stones?

Answer 9

200 to 300 mg per day and single or divided doses. Dosage may be adjusted according to 24 hour urinary urate readings.

Question 10

What is the mechanism of action for allopurinol?

Answer 10

Allopurinol competitively inhibits xanthine oxidase which is the enzyme responsible for the conversion of hypoxanthene to xanthene to uric acid.

Question 11

What are the drug interactions for Zyloprim?

Answer 11

May increase ampicillin induced skin rash. Increases the pharmacological and toxic effects of orally administered thiopurines and chlorpropamide.

Question 12

What are the contraindications of allopurinol?

Answer 12

• Use with caution in patients with impaired renal and hepatic function.
• Gout attacks may increase during initiation of therapy.
• Use colchicine or NSAIDs prophlactiaclly.
• Sufficient fluid intake and the maintenance of a neutral to slightly alkaline urine or recommended to avoid the formation of xanthine calculi and to help prevent renal precipitation of urates in patients receiving uricosuric agents.
• Decrease dosage interval to once to twice a week in patients with severe renal insufficiency.
• Pregnancy Category C

Question 13

What are the adverse effects of allopurinol?

Answer 13

Drowsiness, diarrhea, nausea, vomiting, abdominal pain, rash

Question 14

What should the pharmacist tell the patient when counseling them on the use of allopurinol?

Answer 14

• Compliance with therapy is essential. May take one or more weeks to reach maximum effectiveness
• May be taken with food or milk if GI upset occurs
• May cause drowsiness. Use caution while operating machinery or when mental alertness is required.
• Avoid alcohol while taking this medication
• High fluid intake during therapy is beneficial to help prevent kidney stone formation
• If a dose is missed, skip it and return to normal dosage schedule