The Ministry of Food and Drug Safety and the Korean Cancer Association (KCA) once again warned cancer patients against using fenbendazole, a dog parasiticide.
Korean cancer patients have been rushing to pharmacies to buy fenbendazole after a YouTube video went viral, claiming that the drug cured a U.S. terminal cancer patient.
"All drugs, including anticancer drugs, needs to prove its safety and efficacy through human clinical trials," the ministry said. "However, the anticancer effect of fenbendazole, which has recently been spreading through SNS and YouTube, are the results of tests on cells and animals, not humans."
Anticancer effects and safety claims related to fenbendazole, which are being distributed via YouTube, have not been proved, the ministry added
The regulatory agency also stressed that fenbendazole had not been tested in humans and that there were conflicting reports, including studies that state that the drug promotes liver tumors.
"Fenbendazole has been used for more than 40 years in animals (dogs) and has not been prescribed to humans, so safety in humans cannot be guaranteed," the ministry said. "Also, the claims that suggest that the drug is safe as it has a low body absorption rate of 20 percent are controversial."
Some anticancer drugs also have low body absorption rate, but those drugs can also increase toxicity if the patient takes a high dose, the ministry added.
While fenbendazole may not have any adverse effects in low doses, a prolonged high dose administration may cause side effects such as severe damage to blood, nerves, and liver.
The ministry also warned against the possible side effects that may occur when a patient takes both fenbendazole and anticancer drugs.
"Fenbendazole is known to have anticancer effects by inhibiting the intracellular organs that make up the skeleton of cancer cells, and drugs that have such anticancer effects are already licensed and used," the ministry said. "Pharmaceutical ingredients that have such mechanism include vincristine, vinblastine and vinorelbine, while drugs that have similar ingredients include paclitaxel and docetaxel."
The ministry went on to say, “Together with experts from the KCA, we will continue to guide patients to use an anticancer drug, and not a dog vermicide, to ensure safe and appropriate treatments.”