What are the counseling points for allopurinol (xanthine oxidase inhibitor)?

From the Guidelines

Allopurinol should be taken exactly as prescribed, usually once daily with food to minimize stomach upset, and patients should be aware of the potential for increased gout attacks during the first few weeks of therapy. When counseling patients about allopurinol, the following points should be considered:

• Inform patients to take allopurinol exactly as prescribed, usually once daily with food to minimize stomach upset 1
• Patients should be aware that during the first few weeks of therapy, gout attacks may actually increase temporarily, so their doctor might prescribe additional medication like colchicine to prevent these flares 1
• It's crucial to drink plenty of water while taking allopurinol to help prevent kidney stones and aid in flushing uric acid from the body 1
• Patients should report any skin rash immediately, even if mild, as this could indicate a serious hypersensitivity reaction called Stevens-Johnson syndrome 1
• Regular blood tests will be needed to monitor uric acid levels and kidney function 1
• Patients should inform all healthcare providers about allopurinol use, especially before surgery or if prescribed new medications, as interactions can occur 1
• Alcohol should be limited as it can increase uric acid levels and reduce allopurinol's effectiveness 1
• Allopurinol works by inhibiting xanthine oxidase, the enzyme responsible for uric acid production, which is why consistent daily use is necessary for effective treatment 1
• The recommended starting dose of allopurinol is low (≤100 mg/day) with subsequent dose titration to target over starting at a higher dose 1
• Patients with moderate-to-severe CKD (stage ≥3) should start with a lower dose of allopurinol and titrate upwards as needed 1
• Concomitant antiinflammatory prophylaxis therapy (e.g., colchicine, NSAIDs, prednisone/prednisolone) should be initiated when starting allopurinol to prevent gout flares 1

From the FDA Drug Label

(1) They should be cautioned to discontinue allopurinol tablets and to consult their physician immediately at the first sign of a skin rash, painful urination, blood in the urine, irritation of the eyes, or swelling of the lips or mouth (2) They should be reminded to continue drug therapy prescribed for gouty attacks since optimal benefit of allopurinol tablets may be delayed for 2 to 6 weeks. (3) They should be encouraged to increase fluid intake during therapy to prevent renal stones. (4) If a single dose of allopurinol tablets is occasionally forgotten, there is no need to double the dose at the next scheduled time (5) There may be certain risks associated with the concomitant use of allopurinol tablets and dicumarol, sulfinpyrazone, mercaptopurine, azathioprine, ampicillin, amoxicillin, and thiazide diuretics, and they should follow the instructions of their physician (6) Due to the occasional occurrence of drowsiness, patients should take precautions when engaging in activities where alertness is mandatory. (7) Patients may wish to take allopurinol tablets after meals to minimize gastric irritation

The counseling points for allopurinol are:

• Caution against certain symptoms: Patients should discontinue allopurinol and consult their physician immediately if they experience a skin rash, painful urination, blood in the urine, irritation of the eyes, or swelling of the lips or mouth.
• Continue gout therapy: Patients should continue drug therapy prescribed for gouty attacks, as the optimal benefit of allopurinol may be delayed for 2 to 6 weeks.
• Increase fluid intake: Patients should increase fluid intake during therapy to prevent renal stones.
• Missed dose instructions: If a single dose of allopurinol is occasionally forgotten, there is no need to double the dose at the next scheduled time.
• Concomitant medication risks: Patients should be aware of potential risks associated with concomitant use of allopurinol and certain medications, such as dicumarol, sulfinpyrazone, mercaptopurine, azathioprine, ampicillin, amoxicillin, and thiazide diuretics.
• Drowsiness precautions: Patients should take precautions when engaging in activities where alertness is mandatory due to the occasional occurrence of drowsiness.
• Administration with meals: Patients may wish to take allopurinol after meals to minimize gastric irritation 2

From the Research

Counseling Points for Allopurinol

• Starting dose: The starting dose of allopurinol should be low, with a proposed safe starting dose of 1.5 mg per unit of estimated glomerular filtration rate (GFR) to reduce the risk of allopurinol hypersensitivity syndrome (AHS) 3.
• Dose escalation: The dose of allopurinol can be gradually increased to achieve the target serum urate level in patients who tolerate the initial dose 3.
• Risk of gout flares: Patients who have had a gout flare in the month before starting allopurinol and those commencing allopurinol 100 mg daily may be at higher risk of gout flares and may require anti-inflammatory prophylaxis 4.
• Monitoring: Patients should be monitored for signs of AHS, such as rash, fever, and liver function abnormalities, and for gout flares 3, 4.
• Alternative treatments: Febuxostat may be a suitable alternative to allopurinol for patients with gout and hyperuricemia, particularly those who are intolerant of allopurinol or have contraindications to its use 5, 6, 7.
• Comparison with febuxostat: Febuxostat has been shown to be more effective than allopurinol in lowering serum urate levels and achieving target serum urate concentrations 5, 6, 7.