Fenben lab fenbendazol is a broad spectrum benzimidazole anthelmintic used to treat gastrointestinal parasites in dogs and cats, including giardiasis, roundworms (including Toxocara canis), hookworms (including Uncinaria stenocephala and Ancylostoma caninum), whipworms (Trichuris vulpis), and the tapeworm genus Taenia (but not Dipylidium caninum, a common dog tapeworm). It also has been shown to have antitumor effects and destabilize microtubules, although these claims are still experimental. It is generally well tolerated in pets at regular doses, although occasionally substances released by dying parasites can cause an allergic reaction that requires immediate veterinary attention.

In an attempt to slow or stop cancer growth, some patients try fenbendazole or other medications that inhibit cell division. A number of clinical studies have shown that fenbendazole may be effective against some tumors in animal models, but no evidence exists that it is efficacious in humans. Furthermore, it is not clear whether these benefits are due to fenbendazole itself or to the combination of conventional cancer therapies with which fenbendazole is given.

A few anecdotal reports of cancer patients who have experienced remission after taking fenbendazole have surfaced, but these are difficult to evaluate as they often lack a control group and do not describe the combination of therapies that the patient received at the time. One such case involves a man who was able to discontinue chemotherapy after receiving fenbendazole. It has been proposed that this was due to the drug’s ability to disrupt cell division by blocking the formation of mitotic spindles, structures that bind the chromosomes during cell division and ensure that they are evenly separated at anaphase.

Twitter and Facebook have been constructively used by some cancer patients to share information about dietary supplements and herbs that they believe may benefit their health. However, it is important for physicians to educate patients about the need to carefully select and filter medical information online. They should also discuss the importance of avoiding self-administration of orally ingested products, including dietary supplements and herbal therapies, without a physician’s prescription, in order to prevent unexpected adverse reactions.