Xanthine oxidase inhibitors Flashcards
1
Q
What is the generic and brand name of a xanthine oxidase inhibitors?
A
• Allopurinol (Zyloric)
2
Q
What is the method of action of allopurinol?
A
- Xanthine oxidase metabolises xanthine (purine) → uric acid
* This is inhibited by this class of drugs
3
Q
What is the indication for allopurinol?
A
- Prevention of acute attacks of gout
- Prevent uric acid and calcium oxalate renal stones
- Prevent hyperuricaemia and tumour lysis syndrome associated with chemotherapy
4
Q
What are the contraindications with allopurinol?
A
- Acute attack of gout – do not start then but if already on it patient should carry on taking it
- Recurrent skin rash
- Severe hypersensitivity
- Renal/liver impairment - ↓ dose
5
Q
What are the side effects of allopurinol?
A
- Skin rash/Stevens Johnson syndrome/toxic epidermal necrolysis
- Drug hypersensitivity syndrome
- Fever
- Eosinophilia
- Lymphadenopathy
- Trigger/worsen an acute attack of gout
6
Q
What drugs does allopurinol interact with?
A
- Mercaptopurine – require xanthine oxidase for their metabolism
- Azathioprine – require xanthine oxidase for their metabolism
- Amoxicillin - ↑ chance of skin rash
- ACE inhibitors - ↑ risk of hypersensitivity reaction
- Thiazide - ↑ risk of hypersensitivity reaction
7
Q
Which organ eliminates allopurinol?
A
Kidney
8
Q
What information should be given to patients taking allopurinol?
A
- Take after meals
- Maintain good hydration
- NSAID/colchicine should be prescribed alongside for the 1st month
