Treatment with two common FDA-approved gout medications have been found to cause rapid death to the parasites that cause elephantiasis.

Researchers at the Uniformed Services University (USU) have discovered that sulfinpyrazone and probenecid, both used regularly for gout, have a lethal effect in vitro on the parasitic worms that cause lymphatic filariasis.

Lymphatic filariasis is a highly prevalent and morbid roundworm infection that is present throughout the tropics. The infection causes genital and lower extremity swelling that, in its most severe form, is called elephantiasis. Current global efforts to eradicate lymphatic filariasis are limited by a lack of medications that can kill the adult stages of the worm when given as a short course.

Using a molecular approach, called siRNA inhibition, by which scientists can stop the production of one protein at a time, Dr. Alexander Flynn and colleagues at USU identified an enzyme (UDP-glucuronosyltransferase) within the intestinal tract of filarial worms as being essential for adult worm survival.

Because these gout medications are generic and are generally safe (probenecid is a pregnancy category B drug, which is the same as penicillin), they may be able to kill the adult stages in infected people.

If studies in humans show an ability of these medications to kill adult filarial worms, this discovery could accelerate efforts to eliminate lymphatic filariasis.

"This study suggests that probenecid and sulfinpyrazone, two generally safe medications that have been long-used for gout, may be able to kill adult filarial parasites in infected individuals," according to Army Maj. Alexander Flynn, chief of the Microbiology Hub Kericho, Medical Research Directorate - Africa/Kenya, who conducted the study in Dr. Edward Mitre's laboratory as part of his PhD work in the Molecular and Cellular Biology program at USU. "If future studies show efficacy in pre-clinical and clinical studies, this discovery could help global efforts to eliminate elephantiasis."