Allopurinol: What It Is, How It Works, and What You Need to Know

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 recurring gout or kidney stones caused by excess uric acid. Unlike painkillers that just mask the hurt, allopurinol goes after the root cause—your body’s overproduction of uric acid. That’s why doctors reach for it when flare-ups keep coming back, no matter how much ice you put on your toe.

It works by blocking an enzyme called xanthine oxidase, which turns purines into uric acid. Purines are natural parts of many foods—red meat, seafood, beer—and your body also makes them. When too much uric acid builds up, it forms sharp crystals in your joints, causing that intense, swollen, burning pain of gout. Allopurinol doesn’t stop the pain right away. In fact, you might get more flares at first. But over weeks and months, it lowers the uric acid level enough to stop new crystals from forming, and even slowly dissolve old ones. That’s the long game.

People on allopurinol often need to watch what they eat, drink plenty of water, and avoid alcohol. But it’s not just about diet. uric acid reducer, a category of drugs that lower serum urate levels to prevent gout attacks like allopurinol also interact with other meds. For example, taking it with certain blood pressure pills or antibiotics can raise your risk of rare but serious skin reactions. That’s why your doctor will start you low and go slow, especially if you’re over 60 or have kidney issues.

Some folks think once their gout calms down, they can stop allopurinol. That’s a mistake. Stopping it suddenly can trigger a flare worse than before. It’s a maintenance drug—like statins for cholesterol. You don’t feel it working, but it’s quietly keeping your uric acid in check. And if you’ve had kidney stones from uric acid, allopurinol can cut your risk of new ones by more than half.

There are other drugs for gout, like febuxostat or probenecid, but allopurinol is still the first-line choice for most. It’s been around since the 1960s, studied in tens of thousands of patients, and it’s affordable. Not everyone tolerates it—some get rashes, nausea, or liver changes—but for most, the benefits far outweigh the risks when used correctly.

Below, you’ll find real-world guides on how allopurinol fits into daily life, what to watch for when you’re on it, and how it compares with other treatments. You’ll see how it connects to other conditions like kidney disease, what to do if you miss a dose, and why some people need genetic testing before starting. This isn’t just a drug list—it’s a practical toolkit for managing gout and high uric acid with confidence.