Worm infections may afflict both humans and domestic animals, benzimidazole derivatives refer to a class of drugs that can often be used to treat roundworm, or nematode, cases as well as those due to flatworms, or trematodes. This class of worm medicine has been used for decades, and remain a fairly common treatment in many cases because of their efficacy. Benzimidazole derivatives are so named because they are derived from a single compound, known as benzimidazole.
Drugs in this family tend to have similar chemical structures, but differ in their dosing and other physical properties, such as how well they dissolve in water or are absorbed by the body. They include albendazole, oxibendazole, mebendazole, and flubendazole. Of this class, triclabendazole cannot be used to treat roundworms, and a few compounds, like albendazole and netobimin, may be used to treat liver fluke infections.
These benzimidazole derivatives have a common mechanism of action. They interfere with the construction of cell structures in worms known as microtubules. Microtubules require constant maintenance in order to remain effective, and they are a necessary part of growth and cellular division. Benzimidazole and its related compounds cap off one end of these structures, preventing them from extending, and causing them to disintegrate; this action not only allows these drugs to prevent worms from growing and reproducing, but they can also directly kill the worms through cellular damage.
Often, these pharmaceutical drugs are used in veterinary medicine, but they may also be used in humans as well. Most commonly, they can be used as worm medicine in cases that affect ruminants, such as cows, as well as horses. Benzimidazole derivatives are somewhat less effective when treating infections in other animals, but are sometimes used in cases involving cats, birds, and dogs and may occasionally used in treating both worm and fungal conditions in humans.
Most benzimidazole derivatives are only minimally soluble in water, so they may be applied as a paste or in a liquid suspension. To overcome the fact that these drugs can sometimes have difficulty absorbing into the body, they may be taken in repeated doses, twice a day, for lengths of time lasting as long as several weeks. Consistent dosing in this manner can often effectively treat a variety of worm infections, including those that might be resistant to other medications. This potent efficacy is the reason that many types of benzimidazoles continue to be used, despite their common issues of absorption and solubility.