If you have chronic gout – persistently high levels of uric acid and gout attacks – the most important part of your care is keeping uric acid levels low (below 6.0 mg of uric acid to l dl of blood) in order to stave off future attacks.

Uric acid is formed from purines, substances in animal and plants that the body converts to uric acid during digestion. Some people’s systems produce too much acid; others can’t excrete what it produced. When excess acid remains in the system, it can form crystals that lodge in the joints, causing the pain and inflammation that characterize a gout attack. If gout is left untreated, tophi – deposits of uric acid crystals – can form under the skin around joints and other soft tissues.

Your doctor will likely prescribe long-term medications to keep uric acid levels steady. Because these drugs cause acid level to shift, you won’t start taking them until your acute attack is under control. (To learn how to manage an acute gout attack, click here).

Some patients only experience one gout attack, so physicians may not start long-term drugs until after a second episode occurs.

It can take time for long-term gout medications. You may even have a flare after you start the medication. So, in the meantime, keep taking the medications your doctor prescribes to treat the acute attack as well.

Below are the medication options for chronic gout.

Allopurinol (Lopurin, Zyloprim), the most traditional and widely used medication for lowering uric acid levels, slows the production of uric acid and may dissolve the uric acid crystals in tophi. However, the drug can take three to six months to dissolve the crystals, and during that time, a gout attack may occur. Doctors typically start patients on a low oral dose, increasing it every two to four weeks, as needed to establish safe uric acid levels. It’s a good choice for patients who overproduce uric acid as opposed to those who under-excrete it (the difference is determined by blood or urine tests). Side effects may include skin rash, sleepiness and stomach upset; the latter usually diminishes as your body adapts to the drug.

Rarely, the drug causes a severe allergic reaction, particularly if you already have congestive heart disease, high blood pressure, diabetes, kidney disease, stomach ulcers or other digestive difficulties, or cancer being treated by radiation or chemotherapy. If you experience itching, a skin rash with hives, fever, nausea or muscle pain, call your doctor immediately. Up to 5 percent of patients can’t tolerate the drug.

Febuxostat (Uloric) was approved by the U.S. Food and Drug Administration (FDA) in 2009. It helps prevent uric acid production by blocking an enzyme that breaks down purines into uric acid. Taken orally once daily, febuxostat is safe for people with mild to moderate kidney or liver disease. Side effects can include liver irritation, nausea, joint pain, and rash. Febuxostat has a higher risk of blood clots than allopurinol.

Probenecid (Benemid, Probalan), taken orally, lowers uric acid in the body by increasing the amount excreted in urine. It’s most likely to be used by people who have trouble excreting uric acid, as opposed to those who overproduce it. Some rheumatologists prefer probenecid to allopurinol because it has less dangerous side effects. However, it isn’t recommended for people with kidney disease. Possible side effects include kidney stones, nausea, skin rash, stomach upset and headaches. Patients taking probenecid need to drink at least eight cups of water or other fluid a day to reduce their risk of kidney stones.

Pegloticase (Krystexxa) is used in severe cases of gout when standard medications are unable to lower the uric acid level, a condition known as chronic refactory gout. Pegloticase lowers uric acid quickly and to lower levels than other medications, but it can lose potency over time. The drug is administered every two weeks by intravenous (IV) infusion. The infusion will take about two hours, but you’ll probably be at your doctor’s office for four hours. You’ll receive medications prior to the treatment and be observed afterward to make sure you don’t have reactions to the infusion or an allergic reaction, which may happen within two hours of treatment. Other side effects can include gout flares, nausea, bruising, sore throat, constipation, chest pain and vomiting. Tell your doctor if you have high blood pressure or are planning on becoming pregnant.

What Doctors Choose:

Allopurinol: For patients who overproduce uric acid; have kidney failure, kidney stones or tophi; use aspirin; or who don’t respond to probenecid.

Febuxostat: For patients with mild to moderate kidney or liver disease. Has an effectiveness and side effects similar to allopurinol.

Probenecid: For patients who cannot tolerate allopurinol. NOT for elderly patients; those with kidney failure or kidney stones; those who take aspirin (it blocks the effect of probenecid); those who overproduce uric acid.

Pegloticase: For patients form whom standard medications have failed to lower uric acid levels.