Thiabendazole is an active ingredient with a broad spectrum of applications. It belongs to the benzimidazole group of active ingredients and is used both as a fungicide and as an anthelmintic (worming agent).
What is thiabendazole?
Thiabendazole is an active ingredient with a wide range of applications. It is used both as a fungicide and as an anthelmintic (worming agent). Thiabendazole is present as a white, odorless and tasteless powder. It is readily soluble in water and sparingly soluble in alcohol. Its basic chemical structure is derived from benzimidazole. Benzimidazole is formed from the fusion of benzene with imidazole and serves as a starting material for the synthesis of the benzimidazole derivatives. Thiabendazole is a derivative of benzimidazole. This was previously still included in the list of food additives because it was used as a preservative for treating the peels of citrus fruits and bananas to prevent mold growth. However, it had to be removed from this list and listed as a fungicide, although its use in this regard has not changed. In pharmacology, thiabendazole is used as a vermifuge to control worm infestations.
Pharmacological action
There is partly contradictory information on the pharmacological effect on the human body. According to the Federal Institute for Consumer Health Protection and Veterinary Medicine, the toxicity of thiabendazole is low. In animal experiments, a carcinogenic effect has indeed been found. In humans, however, there is said to be no evidence of carcinogenic, mutagenic or reproductive toxicity effects. In any case, thiabendazole is rapidly absorbed when taken orally and undergoes complete metabolism within 24 hours, with the breakdown products being excreted in the urine. It owes its action as an anthelmintic and fungicide to the disruption of cell growth by its interaction with the microtubules of the cells, although the exact mechanism of action has not yet been fully elucidated. The two different areas of application should also be noted. As a fungicide, thiabendazole is used in agriculture. Here it has a preventive and curative effect as a systemic fungicide for the plant. Systemic means that thiabendazole is transported everywhere via the water transport system of the plants, thereby exerting its fungicidal effect everywhere in the overall system. Thiabendazole can both prevent fungal growth and kill existing fungi. However, in human or animal organisms, thiabendazole is not used as an antifungal (fungicide) agent.
Medicinal use and application
In medicine and veterinary medicine, thiabendazole is mainly used as an anthelmintic (worming agent). One important area of use is strongyloidiasis. Strongyloidiasis is an infestation with the dwarf threadworms Strongyloides stercoralis. The course of the disease can be very dramatic. The larvae of the parasite can pass through the human skin via the bloodstream to the lungs. From there, they migrate via the trachea to the pharynx and then enter the intestine by ingestion. In addition to chronic bronchitis, digestive problems manifest. The severity of the disease also depends on the strength of the immune system. Manifest disease can be well treated with thiabendazole. Furthermore, thiabendazole is used for infestation with threadworms (nematodes), such as trichinosis, toxocariasis in dogs and cats, or other worm diseases. The action of thiabendazole against worms is based on the inhibition of the polymerization of tubulin of the parasites. There is also an influence of thiabendazole on the T-cells of the immune system. The consequences of killing the parasites and the resulting immune responses require constant follow-up examinations. Blood and stool tests can be used to document the healing successes.
Risks and side effects
Thiabendazole is rapidly broken down in the body. Therefore, there is a good chance that long-term effects of its use will not occur. The Federal Institute for Consumer Health Protection and Veterinary Medicine therefore also assumes that the toxicity of thiabendazole is low. However, this statement is in contradiction to studies that it has carcinogenic potential. When used in high doses, however, it can cause growth disorders, infertility and kidney damage.A conclusive assessment of the toxicity of thiabendazole is not yet possible according to the current state of knowledge. However, acute side effects have been observed in some cases of its use, such as nausea, dizziness and faintness. In rare cases, neurotoxic effects such as depression, anxiety, drowsiness, double vision, or even psychotic reactions have also occurred.
