Krystexxa for Gout
Dr. Landis, November 2018
Gout is an arthritis characterized by rapid development of warmth, swelling, joint redness, and severe pain in the joint. The pain is at its most intense 8-12 hours after the first twinges of pain. Gout can be triggered by certain foods, alcohol and trauma to the joint among other things. Left untreated, a gout flare can last days to weeks.
Gout is caused by an elevated uric acid level with deposition of uric acid crystals in the joints. It takes decades of uric acid crystal deposition before a person with gout will have a flare. While men generally start having gout flares in the 4th to 6th decade of life, it is very rare for a woman to have a gout flare prior to menopause.
Gout treatment with a uric acid reducing agent does not start with high uric acid levels until the uric acid level is above 13. Treatment is initiated when the uric acid level is above 13 due to the higher risk of developing uric acid kidney stones.
Treatment with uric acid lowering therapy is initiated when the patient has 3 or more flares of gout a year or if they have a gout flare in more than 1 joint at a time. Gout usually starts with a single flare and then the next flare will be years later. Gout flares will become more frequent, last longer, and be more painful with time.
Treatment with uric acid lowering therapy is also initiated if a patient develops tophi. A tophus is a nodule which is full of uric acid crystals. They are commonly found on the elbows, but can be found anywhere in the body. Tophi usually start around 10 years after the first gout flare, though not everyone with gout will develop tophi.
Treatment for an acute gout flare is usually with a high dose NSAID’s or steroids. If uric acid lowering is indicated, the uric acid lowering agents are started after the flare is over. At the initiation of uric acid lowering therapy, colchicine is started to prevent flares associated with the start of a uric acid lowering agent.
Allopurinol and Uloric inhibits an enzyme that create uric acid lowering uric acid levels. Probenecid and Zurampic will help excrete uric acid through the kidneys, but a normal renal function is required and the patient needs to drink 2 liters of water a day.
Krystexxa is a unique treatment for gout. Animals have an enzyme called uricase which changes uric acid to a substance that can be excreted through the kidneys. Scientists worked decades to develop a way that uricase could be given to humans. They tried multiple ways to prevent allergic reaction and elimination of the uricase. The result of this scientific effort is Krystexxa.
Krystexxa will drop the uric acid to undetectable levels. However, there is a risk of an allergic reaction to this medication. If the uric acid level does not stay below 6 when measured 2 weeks after the infusion, there is a risk of allergic reaction with the next infusion and the Krystexxa treatment will be stopped.
Krystexxa is used when other medications cannot be used or the patient has significant, debilitating tophi. Other uric acid reducing agents take years or even decades to dissolve tophi. Krystexxa can dissolve tophi in months. This is important for the patients with tophi in the fingers or other areas causing bone and joint destruction. The tophi can limit the ability of the patient to get their daily activities done and the patient can be disabled from performing these activites. Krystexxa can reverse the tophi’s detrimental effects and bring a significant amount of function back to the patients joints. Krystexxa can make a significant impact in patient’s lives.