Should allopurinol and colchicine be avoided when taken together?

From the Guidelines

Allopurinol and colchicine can be taken together, and this combination is often prescribed for gout management. Colchicine is typically used for acute gout flares or as prophylaxis when starting allopurinol, while allopurinol works as a long-term uric acid-lowering therapy. When initiating allopurinol, doctors often prescribe colchicine (typically 0.6 mg once or twice daily) for the first 3-6 months to prevent gout flares that can occur as uric acid levels change. This combination works well because the medications have different mechanisms: allopurinol inhibits xanthine oxidase to reduce uric acid production, while colchicine reduces inflammation by interfering with neutrophil function and inflammatory pathways. However, dose adjustments may be needed for both medications in patients with kidney impairment. Side effects to watch for include gastrointestinal symptoms (particularly with colchicine), rash, and liver function abnormalities. Always take these medications as prescribed and inform your doctor of any side effects. According to the study by 1, allopurinol is an appropriate long-term urate-lowering therapy, and colchicine can be used for prophylaxis against acute attacks during the first months of urate-lowering therapy, as supported by 1.

Some key points to consider when taking allopurinol and colchicine together include:

• Starting with a low dose of allopurinol (100 mg daily) and increasing as needed to minimize the risk of acute attacks and toxicity, as recommended by 1
• Monitoring for side effects, such as gastrointestinal symptoms, rash, and liver function abnormalities, as noted in 1 and 1
• Adjusting doses as needed for patients with kidney impairment, as suggested by 1
• Considering alternative urate-lowering treatments if allopurinol toxicity occurs, as discussed in 1

Overall, the combination of allopurinol and colchicine can be an effective treatment for gout management, but it's essential to carefully monitor patients for potential side effects and adjust treatment as needed, based on the evidence from 1 and 1.

From the FDA Drug Label

In addition, it is recommended that the patient start with a low dose of allopurinol tablets (100 mg daily) and increase at weekly intervals by 100 mg until a serum uric acid level of 6 mg/dL or less is attained but without exceeding the maximum recommended dose (800 mg per day). The use of colchicine or anti-inflammatory agents may be required to suppress gouty attacks in some cases Accordingly, maintenance doses of colchicine generally should be given prophylactically when allopurinol tablets are begun

No, you should not avoid taking allopurinol and colchicine together. In fact, the label recommends giving maintenance doses of colchicine prophylactically when allopurinol is begun, to suppress gouty attacks. 2

From the Research

Interaction between Allopurinol and Colchicine

• The use of colchicine with allopurinol may increase the risk of adverse events, as shown in a study published in the Journal of Clinical Pharmacology 3.
• This study found that patients who used colchicine with allopurinol had a higher risk of developing adverse events, with an odds ratio of 3.11 (95% confidence interval, 1.28-7.58; P = .012).
• Another study published in Arthritis Care & Research 4 described the clinical characteristics and health care utilization patterns of patients with gout who were newly prescribed allopurinol, febuxostat, or colchicine, but did not specifically address the interaction between allopurinol and colchicine.
• A review of the current treatments for gout, including allopurinol and colchicine, was published in Expert Opinion on Pharmacotherapy 5, but did not provide information on the safety of using these medications together.

Safety Considerations

• Patients who use colchicine with allopurinol should be monitored closely for adverse events, as the combination of these medications may increase the risk of serious side effects 3.
• The safety of using allopurinol with colchicine has not been extensively studied, and more research is needed to fully understand the potential risks and benefits of this combination.
• Other studies have investigated the safety and efficacy of allopurinol and febuxostat in patients with gout, including those with diabetes 6, 7, but did not address the specific interaction between allopurinol and colchicine.