Pegloticase for Gout
Most gout patients respond to conventional gout treatments like uric acid inhibitors and uricosuric drugs usually administered as tablets and capsules. There are however chronic gout sufferers that do not respond well to any of these conventional treatments.
These are patients that have refractory chronic gout (RCG). RCG is marked by frequent flares, tophi, consistently high uric acid and non-response to conventional treatments. In the US alone, there are about 3% of three million adult gout sufferers that have RCG. They are the targeted beneficiary of a US FDA-approved Pegloticase drug marketed under the brand name Krystexxa (formerly Puricase).
Pegloticase is a recombinant porcine-like uric oxidase enzyme or uricase. It metabolizes uric acid to allantoin that can be easily excreted via the urine. Krystexxa in particular is different from conventional gout medications in that it is given intravenously (via IV).
Pegloticase for Gout – Dosage
Recommended dosage is 8 mg administered intravenously over two hours, once every two weeks. Since it is given intravenously, there is risk of infusion as well as allergic reactions. Patients undergoing this treatment are monitored for any of these reactions and infusion is stopped and restarted at lower rate if any reactions are observed.
They may also be given anti-allergic drugs prior to treatment if they are known to be allergic to Pegloticase. In clinical trials of Krystexxa, severe allergic reaction by one patient necessitated the administration of antihistamine.
Pegloticase for Gout – Side Effects
It is associated with gout flares, infusion reactions and anaphylaxis (extreme allergic reaction). Other side-effects such as nausea, vomiting, constipation, chest pain, contusion and nasopharyngitis were also reported. It is contra-indicated in patients with G6PD deficiency (also named favism) a genetic disorder linked to hemolytic anemia in people with African and Mediterranean descent.
It has also been observed to worsen congestive heart failure as reported in two gout patients with the condition treated with Pegloticase. In the absence of a detailed study, patients with congestive heart disease must be closely monitored when under this medication. It is also not allowed for pregnant and breastfeeding women as well those planning to get pregnant.
There are also other uricase used to treat gout like Rasburicase marketed under the brand name Elitek in the US and Fasturtec in Europe. It is primarily used for treatment of tumor lysis syndrome (TLS) in patients receiving chemotherapy for leukemia and lymphoma. It also converts uric acid into allantoin just like Pegloticase.
Gout patients can only benefit from a host of treatments now available in the market. The best course of action is to discuss with your health care provider the options available and all possible benefits and risks from each option.