Allopurinol Therapy Considerations

Patient Selection and Dosing

The American College of Physicians recommends that patients with decreased renal function require dose reductions, starting at 50 mg daily for stage 4 or worse CKD 2
The FDA recommends at least 50% dose reduction in patients with renal insufficiency, and the American Society of Nephrology suggests that renal function monitoring should be performed periodically 3
Patients with HLA-B5801 haplotype have increased risk for serious adverse effects, and the American College of Rheumatology suggests that rapid PCR-based HLA-B5801 screening should be considered before initiating allopurinol in these high-risk populations 1, 2

The American Society of Clinical Oncology recommends that concomitant use with mercaptopurine or azathioprine requires 65-75% dose reduction of the chemotherapeutic agent due to severe myelotoxicity risk 3, 4
The American Heart Association suggests that warfarin may require increased dosing and more frequent INR monitoring when used with allopurinol 4

The National Kidney Foundation recommends starting with low doses (100 mg daily, or 50 mg daily in stage 4+ CKD) and titrating gradually at weekly intervals, and maintaining adequate fluid intake to yield at least 2 liters daily urinary output to prevent xanthine calculi formation 2
The American College of Physicians suggests that patients should be observed closely during early stages of therapy, particularly those with impaired renal function 2