Cat medication proves promising in treating parasitic worms in humans

Saturday May 27 2023

Drug resistance over common anthelminthics has been on the rise. PHOTO | SHUTTERSTOCK


For decades the only treatments readily available for the treatment of infections by parasitic worms have been Albendazole and Mebendazole.

Albendazole, first introduced in 1977 to treat soil-transmitted helminth infections in sheep, was registered for human use in 1982, while Mebendazole came into use in 1971. The two works by blocking worms from using glucose, hence killing them.

These two are the current recommended treatments for parasitic worms by the World Health Organisation (WHO).

However, in the case of the whipworm (Trichuris trichiura), a single dose of these drugs can only cure 17 percent of the infected people. Moreover, drug resistance is on the rise, and new alternative treatments are urgently needed.

Mebendazole is the drug of choice for treating whipworms but a single 500mg dose can result in a cure rate of 40-75 percent. Albendazole, the alternative drug, has a slightly lower efficacy.

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New study

Researchers have now been testing efficacy of the drug emodepside on people infected with one or more of the three main soil-transmitted helminths: whipworm, hookworm and roundworm. Emodepside is an anthelmintic licensed for use in cats against gastrointestinal roundworms and hookworms.

The study conducted in Tanzania by the Swiss Tropical and Public Health Institute (Swiss TPHE) together with the Public Health Laboratory Ivo de Carneri (PHL-IdC) and published last week in the New England Journal of Medicine found high cure rates for all three soil-transmitted helminths.

The lowest dose tested, 5mg of emodepside, cured 83 percent of people infected with whipworm.

“An increase of emodepside to 15mg resulted in complete cure of all people. Curing people infected with whipworm has never been achieved with the current anthelminthic treatments. In addition, high efficacy was also observed against roundworm and hookworm,” said study lead Emmanuel Mrimi.

“The drug is well tolerated and most adverse events in the trial were mild.”

Swiss TPH says the veterinary drug showed potential in laboratory studies to treat patients infected with soil-transmitted helminths.

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“Drug repurposing is a key strategy in research for anthelminthic drug discovery and development that is neglected and underfunded,” said head of the Helminth Drug Development unit, Jennifer Keiser, “Most repurposed drugs come from veterinary medicine.”

“The recent results of the clinical trials are important and good news in the field of neglected tropical diseases. No new anthelminthic has been developed in the past decades. So, this is a huge milestone towards controlling and eliminating soil-transmitted helminthiases.”

Swiss TPH has said it will join forces with the life science company Bayer on the further development of the drug to have it approved for use in humans.

Worldwide, more than 1.5 billion people are infected with at least one soil-transmitted helminth, with most of the infected population living in low- and middle-income countries.