10.8 Gout

Question 1

Is the mechanism of colchicine well known? What protein does it bind to, and is this more related to its toxicity of therapeutic effect?

Answer 1

• Mechanism not well known
• Binds to tubulin; inhibits mitosis
• This is more related to toxicity

Therapeutic effect comes from reducing inflammatory reaction to CPP or Sodium Urate crystals.

Question 2

Why is the clearance of colchicine strange? How soon can we deprescribe it?

Answer 2

Because it is both renally and hepatically cleared to some extent.

We can deprescribe it suddenly.

Question 3

Side effects of colchicine (acute vs chronic)

Answer 3

Acute: diarrhoea, vomiting
Chronic: myalgia, weakness

Question 4

Colchicine toxicity side effects

Answer 4

• Kidney/liver failure (makes sense: clearance)
• Bone marrow suppression

Question 5

Which two drugs cannot be prescribed alongside xanthine oxidase inhibitors?

Answer 5

• Azathioprine
• Mercaptopurine

Question 6

Is a rash always a super bad sign with allopurinol? What do you do if a rash comes up?

Answer 6

• No, not always a bad sign, but it might be start of hypersensitivity reaction.
• Stop allopurinol immediately