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. Allopurinol is 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). It is not recommended for people with congestive heart failure, severe kidney disease or liver disease. 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 or other serious side effects. 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) 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. Your doctor is most likely to prescribe it if you have trouble excreting uric acid, as opposed to overproducing 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.
Lesinurad (Zurampic) is an oral drug that increases excretion of uric acid by inhibiting a protein called urate transporter 1 (URAT1), which is responsible for the majority of uric acid reabsorption by the kidneys. It is used along with a xanthine oxidase inhibitor (XOI), such as allopurinol or febuxostat, to enhance the effects for people whose gout is not controlled by optimally-dosed XOIs alone. Lesinurad should NOT be used without an XOI, because of an increased risk of side effects such as increased blood creatinine and kidney-related side effects including renal insufficiency. Patients should stay well hydrated to avoid formation of kidney stones. Lesinurad may also increase the risk of cardiovascular events.
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 refractory 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.