Approximately six million Americans suffer from gout, the most common form of inflammatory arthritis. Although gout is most often associated with pain, it is now thought that the condition also increases risk for hypertension and cardiovascular disease.
What Is Gout?
Gout occurs when uric acid, a by-product of metabolism, is produced in excessive amounts or when it is not excreted efficiently by the kidneys. A buildup of uric acid causes the formation of urate crystals in the fluid that lubricates joints. These crystals can trigger an immune response that causes inflammation and excruciating pain.
Gout often strikes at the base of the big toe, causing pain that increases for eight to 12 hours and subsides within three to 10 days without treatment. Other joints can also be affected. The attacks are intermittent and unpredictable. They may occur every few weeks or months, once or twice a year or every few years. But without treatment, the attacks generally increase in duration as well as frequency.
The risks: Untreated gout can cause permanent joint damage. Some patients progress from recurrent gout to tophaceous gout, a severe form in which lumps of urate crystals form in and around joints or even under the skin. Gout increases the risk for kidney stones, and patients who don't achieve good control of their elevated uric acid levels are more likely to develop cardiovascular disease than those without gout.
Easy To Diagnose
Patients who are suspected of having gout are usually advised to have a blood test to measure uric acid. However, some asymptomatic patients have high levels of uric acid, while those in the midst of an attack may have apparently normal levels (3 mg/dL to 7 mg/dL). Typically, the uric acid level peaks around two weeks after an acute attack.
Joint aspiration is the best test for gout, especially in its early stages. Your doctor will insert a needle into the inflamed joint (lidocaine and numbing sprays minimize the pain of the needle) and withdraw fluid, which is then examined under a microscope. The presence of urate crystals means that you have gout, regardless of the uric acid concentrations in your blood.
Ultrasound is now used by some doctors to diagnose gout. It's painless and completely noninvasive. It's good for detecting gout (which may not be evident with a physical exam), but harder to diagnose in the early stages without joint aspiration.
Treating gout is a two-step process. Depending on the severity of the attack, various medications can be used to reduce pain and inflammation.
Examples: Nonsteroidal anti-inflammatory drugs, such as ibuprofen (Motrin)...colchicine (Colcrys), the oldest medication used for treating gout...and corticosteroids, which serve as fast-acting anti-inflammatories.
To reduce uric acid, medications such as the following are taken one to two weeks after a gout attack (using these drugs during a gout attack can worsen symptoms)...
- Febuxostat (Uloric) is the first new oral drug for gout in 40 years. Taken daily, it can reduce uric acid to an optimal level within a few weeks. Most people with gout need to continue taking this drug indefinitely, but in rare cases it can be discontinued after about a year without subsequent flare-ups.
- Allopurinol (Zyloprim, Aloprim), like febuxostat, reduces uric acid concentrations. It's much less expensive than febuxostat ($40 versus $185 for 30 tablets), and it works well for most patients. It usually takes at least six to eight weeks to see a reduction in uric acid levels and may take subsequent dose increases to reduce uric acid to an appropriate level. An older gout drug, allopurinol is more likely to cause kidney problems than febuxostat.
- Probenecid (Benemid, Probalan) increases the excretion of uric acid by the kidneys. Most patients who take it can achieve reductions in uric acid levels within two weeks. Potential side effects include kidney stones, gastrointestinal upset and rash. Probenecid can't be taken by patients with kidney disease.
- Pegloticase (Krystexxa) has just been approved by the FDA for the treatment of refractory gout, which can't be managed with other approaches. It's given by intravenous infusion once every two weeks. Side effects may include nausea, confusion and vomiting.