When you start allopurinol, a xanthine oxidase inhibitor used to lower uric acid levels in the body. Also known as Zyloprim, it’s one of the most common drugs prescribed for gout and kidney stones caused by too much uric acid. But starting it isn’t as simple as popping a pill. Many people get flare-ups in the first few weeks—not because the drug isn’t working, but because it’s actively breaking down old uric acid crystals. This triggers inflammation before it calms down. That’s why doctors often pair it with low-dose colchicine or NSAIDs at the beginning.
Allopurinol works by blocking the enzyme that turns purines into uric acid. If you eat a lot of red meat, shellfish, or drink beer regularly, your body makes more uric acid than it can flush out. Over time, that builds up as sharp crystals in your joints, causing the pain and swelling of gout. Allopurinol doesn’t treat the pain right away—it prevents future attacks. It’s not a quick fix. It’s a long-term tool, often taken for years. People with kidney disease, high blood pressure, or who’ve had multiple gout attacks are the ones who benefit most. But it’s not for everyone. If you’ve had a severe allergic reaction before, like a rash that spread or blisters, you should avoid it. The FDA has warned about a rare but dangerous skin reaction called Stevens-Johnson syndrome, especially in people with the HLA-B*5801 gene variant, which is more common in people of Asian descent.
When you start allopurinol, a xanthine oxidase inhibitor used to lower uric acid levels in the body. Also known as Zyloprim, it’s one of the most common drugs prescribed for gout and kidney stones caused by too much uric acid. But starting it isn’t as simple as popping a pill. Many people get flare-ups in the first few weeks—not because the drug isn’t working, but because it’s actively breaking down old uric acid crystals. This triggers inflammation before it calms down. That’s why doctors often pair it with low-dose colchicine or NSAIDs at the beginning.
Allopurinol works by blocking the enzyme that turns purines into uric acid. If you eat a lot of red meat, shellfish, or drink beer regularly, your body makes more uric acid than it can flush out. Over time, that builds up as sharp crystals in your joints, causing the pain and swelling of gout. Allopurinol doesn’t treat the pain right away—it prevents future attacks. It’s not a quick fix. It’s a long-term tool, often taken for years. People with kidney disease, high blood pressure, or who’ve had multiple gout attacks are the ones who benefit most. But it’s not for everyone. If you’ve had a severe allergic reaction before, like a rash that spread or blisters, you should avoid it. The FDA has warned about a rare but dangerous skin reaction called Stevens-Johnson syndrome, especially in people with the HLA-B*5801 gene variant, which is more common in people of Asian descent.
It also interacts with other meds you might be taking. If you’re on azathioprine for autoimmune issues, allopurinol can make it way too strong—dangerously suppressing your immune system. If you take warfarin, your blood thinner, allopurinol can increase its effect and raise bleeding risk. Even common painkillers like aspirin can interfere. And if you’re on diuretics like hydrochlorothiazide, your risk of side effects goes up. That’s why your doctor needs to know every pill, supplement, or herb you’re using.
Most people tolerate allopurinol fine once they get past the first month. But you still need to drink plenty of water—aim for at least 2 liters a day—to help your kidneys flush out the broken-down crystals. Skipping doses or stopping early because you feel fine can lead to worse flare-ups later. It’s not a drug you take for a week and forget. It’s a commitment.
Below, you’ll find real-world advice from people who’ve been through it: how to manage side effects, what to do if you miss a dose, how it compares to febuxostat, and when to call your doctor instead of waiting it out. These aren’t theoretical guides—they’re from patients who’ve learned the hard way. Whether you’re just starting or been on it for a while, there’s something here that’ll help you stay on track.
Nov, 18 2025
Learn how to safely start allopurinol therapy for gout with step-by-step guidance on dosing, preventing flares, spotting side effects, and long-term management. Start low, stay consistent, and avoid common mistakes.
