Allopurinol: What It Is, How It Works, and Alternatives for Gout and High Uric Acid

When your body makes too much allopurinol, a xanthine oxidase inhibitor used to lower uric acid levels in the blood. Also known as Zyloprim, it’s one of the most prescribed drugs for people with frequent gout attacks or kidney stones caused by excess uric acid. It doesn’t treat pain during a flare—it stops the root cause: too much uric acid building up. That’s why doctors often prescribe it long-term, not just when you’re in pain.

Allopurinol works by blocking an enzyme called xanthine oxidase, which turns purines into uric acid. Less enzyme activity means less uric acid in your blood. That’s why it’s used not just for gout, but also in cancer patients getting chemotherapy—when cells break down fast, uric acid spikes. People with kidney disease or those who’ve had multiple gout attacks over years often stay on it for life. But it’s not for everyone. Some get rashes, nausea, or worse, a rare but serious skin reaction called Stevens-Johnson syndrome. If you get a rash while taking it, stop and call your doctor right away.

There are other ways to manage high uric acid. febuxostat, a newer alternative to allopurinol that also blocks uric acid production is often used when allopurinol doesn’t work or causes side effects. Then there’s probenecid, a drug that helps your kidneys flush out uric acid instead of blocking its creation. It’s better for people whose kidneys still work well but can’t clear uric acid fast enough. And don’t forget lifestyle: cutting back on red meat, shellfish, beer, and sugary drinks can make a big difference—even if you’re on medication.

Many people assume that once their gout flare goes away, they can stop the pill. But that’s when the real work starts. Stopping allopurinol suddenly can trigger a worse flare. It takes months for uric acid crystals to dissolve, and you need steady levels to keep them from reforming. That’s why consistency matters more than the dose. Some folks do fine on 100mg a day. Others need 300mg or more. Your doctor will adjust based on your blood test results—not how you feel.

What you won’t find in most brochures: allopurinol can interact with other meds. If you’re on azathioprine or mercaptopurine (used for autoimmune diseases or cancer), allopurinol can make them dangerously strong. If you’re on blood pressure meds like lisinopril-HCTZ, you’re already at higher risk for gout—and allopurinol might be the fix. But if you’re on diuretics, your doctor needs to monitor you closely. And if you’ve ever had a bad reaction to allopurinol, don’t try another xanthine oxidase inhibitor. Switching to febuxostat might be safer.

Below, you’ll find real comparisons between allopurinol and other treatments, stories from people who’ve managed gout for years, and clear advice on avoiding side effects. Whether you’re just starting out or have been on it for a while, these posts give you the facts without the fluff.