Allopurinol

Question 1

allopurinol indications

Answer 1

• prophylaxis- to prevent acute attacks of gout
• prevent uric acid and calcium oxalate renal stones
• prevent hyperuricaemia and tumour lysis syndrome associated with chemotherapy

Question 2

allopurinol indications

Answer 2

• prophylaxis- to prevent acute attacks of gout
• prevent uric acid and calcium oxalate renal stones
• prevent hyperuricaemia and tumour lysis syndrome associated with chemotherapy

Question 3

allopurinol side effects

Answer 3

• skin rash
• hypersensitivith: steven johnson syndrome
• toxic epidermal necrolysis
• starting allopurinol can trigger or worsen acute attack of gout

Question 4

allopurinol warnings

Answer 4

• should not be started during acute attacks of gout - want to AVOID sudden fluctuations in serum uric acid levels
• metabolised in liver and excreted by the kidneys ( dose reductions in respective impairments(

Question 5

allopurinol important interactions

Answer 5

• mercaptopurine is pro drug
  azathipprine require xanthine oxidase for metabolism : increased risk of toxicity because metsbolism is increased
• allopurinol and amoxicillin co prescription = increased risk of skin rash
• allopurinol and ACE inhibitors or thiazides increase risk of hypersensitivity reaction

Question 6

prescribing guidance for allopurinol

Answer 6

• NSAID or Colchicine prescribed and continued for at least one month after serum uric acid levels return to normal to avoid triggering acute attack
  -though allopurinol should not be started during an acute attack, pts already on it should continue taking it
• where part of cancer treatment, commenced before chemotheraoy

Question 7

administration of allopurinol

Answer 7

take after meals
good hydration
fluid intake 2-3 litres daily

Question 8

administration of allopurinol

Answer 8

take after meals
good hydration
fluid intake 2-3 litres daily

Question 9

monitoring of allopurinol

Answer 9

• serum uric acid conc checked 4 weeks after initiation
• aim for uric conc less than 30p
  -stop allopurinol if rash develops

Question 10

clinical tip for allopurinol

Answer 10

treatment with thiazide or loop diuretics :
- can increase uric acid concentrations and can cause gout
- low dose aspirin inhibits renal excretion of uric acid and can trigger acute attacks of gout
- consider drug induced gout in patients with new onset jount pain taking these medicines