| Acute and Chronic Gout
Take great care in starting. There is a risk of SJS or TEN (Asian HLA-B*5801 allele) and there are also several potentially lethal drug interactions with Allopurinol and Azathioprine or Mercaptopurine or Ciclosporin. Side effects are rash, pruritus, cytopenia, diarrhoea, toxic epidermolysis and Stevens-Johnson syndrome.
- Its metabolite alloxanthine is the active drug
- ****Can be lethal if given with other drugs see below****
- Blocks the conversation of xanthine to uric acid
- Xanthine oxidase inhibitor reducing uric acid production from purines
Indications/Dose: Check BNF
- Chronic gout: Allopurinol 100-300 mg od po with food. Max 900 mg/day.
- Do not start as single agent until at least 4 weeks after acute gout.
- Use lowest dose to keep uric acid <6 mg/dL.
- Acute Episode: An NSAID or low dose of Colchicine can be given for a month initially along with Allopurinol 100 mg to prevent acute attacks.
- Tumour lysis syndrome: Allopurinol 100-300 mg 8 h.
- This is not an innocuous drug and should not be used for asymptomatic hyperuricaemia
| Allopurinol||100-200 mg (max dose 300 mg TDS)||OD||PO|
| Allopurinol||50 mg starting dose in Elderly||OD||PO|
- Acute gout. If an attack happens on Allopurinol there is no need to stop Allopurinol.
- If starting following acute attack then combined with Colchicine or NSAID
- Ensure adequate fluid intake.
- Reduce dose in Renal Impairment and Liver disease
- Be careful as there is the potential for severe fatal toxicity if given with Azathioprine, Mercaptopurine or Ciclosporin. Doses will need adjusting.
- Can cause Azathioprine toxicity - LETHAL WARNING
- Can cause 6 Mercaptopurine toxicity - LETHAL WARNING
- Can affect Warfarin levels - watch INR
- Can increase levels of ACEI/AT2 antagonists
- Can increase levels of cyclophosphamide
- Acute gout, Rash rarely Stevens-Johnson syndrome - stop the drug if rash develops
- Interstitial nephritis, Hepatitis, Eosinophilia, Gynaecomastia, Metallic taste in the mouth
- Drug Rash with Eosinophilia and Systemic Symptoms (DRESS)
- Generalized vasculitis, irreversible hepatotoxicity,