From the Guidelines
Allopurinol is effective in controlling uric acid levels, and it is recommended as the first-line treatment for uric acid reduction, starting at a low dose of 100 mg/day and increasing as needed to reach the target uric acid level of <6 mg/dL. According to the 2016 updated EULAR evidence-based recommendations for the management of gout 1, allopurinol is the preferred choice for uric acid reduction due to its efficacy, low cost, and safety. The medication works by inhibiting xanthine oxidase, the enzyme responsible for converting purines into uric acid, thereby reducing uric acid production.
Some key points to consider when using allopurinol to control uric acid levels include:
- Starting at a low dose of 100 mg/day and increasing by 100 mg increments every 2-4 weeks as needed to reach the target uric acid level of <6 mg/dL 1
- Monitoring uric acid levels regularly to ensure the target level is reached and maintained 1
- Adjusting the dose of allopurinol based on kidney function, with reduced doses recommended for patients with renal impairment 1
- Considering alternative treatments, such as febuxostat or a uricosuric, if allopurinol is not tolerated or effective 1
It's also important to note that allopurinol is a long-term treatment for conditions like gout, and regular blood tests to monitor uric acid levels and liver and kidney function are necessary during treatment. Overall, allopurinol is a effective and recommended treatment for controlling uric acid levels, and it should be used in accordance with the EULAR guidelines and under the supervision of a healthcare professional 1.
From the FDA Drug Label
Allopurinol tablets reduce serum and urinary uric acid concentrations. Administration of allopurinol tablets generally results in a fall in both serum and urinary uric acid within 2 to 3 days. Allopurinol tablets reduce both the serum and urinary uric acid levels by inhibiting the formation of uric acid
Allopurinol can control uric acid by reducing serum and urinary uric acid concentrations through the inhibition of uric acid formation. The degree of this decrease can be manipulated almost at will since it is dose-dependent 2, 3.
From the Research
Allopurinol's Effect on Uric Acid
- Allopurinol has been shown to decrease serum uric acid levels by inhibiting the enzyme xanthine oxidase 4.
- A prospective, randomized, controlled trial of 54 hyperuricemic patients with chronic kidney disease found that allopurinol significantly decreased serum uric acid levels from 9.75 +/- 1.18 mg/dL to 5.88 +/- 1.01 mg/dL (P < 0.001) 4.
- Another study compared the effectiveness of allopurinol and febuxostat in gout management, and found that allopurinol was noninferior to febuxostat in controlling flares, with 36.5% of allopurinol-treated participants experiencing one flare or more compared to 43.5% of febuxostat-treated participants (P<0.001 for noninferiority) 5.
Comparison with Other Treatments
- A retrospective cohort study compared the safety and efficacy of febuxostat, allopurinol, and benzbromarone in Chinese gout patients, and found that febuxostat (40 mg) had a similar treatment effect and total rate of adverse events to allopurinol or benzbromarone 6.
- A systematic review compared the long-term renal outcomes of allopurinol and febuxostat in patients with hyperuricemia and chronic kidney disease, and found that febuxostat may be more renoprotective than allopurinol based on evidence from small long-term retrospective studies with serious risk of bias 7.
- A randomized controlled trial compared febuxostat, allopurinol, and placebo in individuals with higher urinary uric acid excretion and calcium stones, and found that febuxostat led to a significantly greater reduction in 24-hour urinary uric acid (-58.6%) than either allopurinol (-36.4%; P=0.003) or placebo (-12.7%; P<0.001) 8.
Key Findings
- Allopurinol is effective in lowering serum uric acid levels and controlling flares in gout patients 4, 5.
- Allopurinol has a similar treatment effect and total rate of adverse events to febuxostat and benzbromarone in Chinese gout patients 6.
- Febuxostat may be more renoprotective than allopurinol in patients with hyperuricemia and chronic kidney disease, but more methodologically rigorous studies are needed to determine the clinical applicability of these results 7.