Allopurinol: What It Is and How It Works

Allopurinol is a pill that lowers uric acid in your blood. High uric acid can cause gout attacks or kidney stones, so doctors often use this drug to keep levels steady. The medicine works by blocking an enzyme called xanthine oxidase, which turns purines from food into uric acid. With the block in place, less acid is made and existing crystals dissolve over time.

When Doctors Prescribe Allopurinol

If you’ve had a painful gout flare‑up, your doctor might suggest allopurinol as a long‑term fix rather than just pain relief. It’s also used for patients with kidney problems caused by uric acid buildup and sometimes for certain chemotherapy protocols where rapid cell turnover spikes acid levels. Your doctor will check blood tests first to make sure the drug is safe for you, especially if you have liver issues or are on other meds that affect kidneys.

How to Take Allopurinol Safely

Take allopurinol exactly as your prescription says—usually once a day after dinner. Starting with a low dose helps avoid sudden drops in uric acid, which can actually trigger a gout flare. Your doctor may raise the dose gradually while watching blood work every few weeks.

Stay hydrated; drinking plenty of water helps flush out any excess uric acid and reduces the chance of kidney stones. Avoid foods high in purines like red meat, organ meats, and certain seafood while you’re on the drug. Alcohol, especially beer, can also raise uric acid, so limit it.

Side effects are usually mild but watch for a rash, fever, or unusual tiredness. A serious skin reaction is rare but needs immediate medical attention. If you notice any swelling, shortness of breath, or severe itching, call your doctor right away.

Don’t mix allopurinol with certain antibiotics such as amoxicillin‑clavulanate without checking first—some combos can cause a rash. Also tell your pharmacist about over‑the‑counter meds like aspirin; even low doses can interfere with how the drug works.

If you miss a dose, take it as soon as you remember unless it’s almost time for the next one. Never double up to make up for a missed pill—you’ll just increase side‑effect risk.

Most people feel better within weeks, but the full benefit may take several months. Keep your follow‑up appointments so your doctor can fine‑tune the dose and confirm that uric acid levels are where they should be.