What is an Anthelmintic?

An anthelmintic is medicine that rids the body of parasites or worms, and might also be called an anti-parasitic or a dewormer. These medicines are used in human and other animal populations to destroy parasites that live in the body. More than one drug may be targeted to address parasitic infections because parasites can become resistant to drug treatment over time.

The question with any type of anthelmintic is how to kill and remove parasites without sickening the infected person or animal. One way to approach this means giving medicines in very small doses that will not affect the parasitic host. It should be noted, though, that overdose of anti-parasitics can be exceptionally dangerous to the person taking them. Dosage must be properly controlled to avoid this.

What type of anthelmintic gets prescribed varies by parasite. Still there are about five drugs that are most commonly prescribed to treat worm infections. These are praziquantel, diethylcarbamazine, ivermectin, mebendazole and albendazole, and there are other drugs available when these are ineffective. Each anthelmintic belongs to a class, but class doesn’t necessarily describe types of worms treated. Instead it may describe action of the drug or at what stage in the parasite’s life cycle the drug can be used. Some drugs are broad spectrum while others are tailored to kill one or two types of parasites at most.

One of the problems with anthelmintics is that many of the drugs have been used for a long time and over time parasites can develop drug resistance. Both animal caretakers and the medical world were relieved to see a new class of these drugs arrive in the early 2000s. Especially where parasitic infection occurs frequently, which is often the case in human populations in developing countries or in animal populations, it’s possible to encounter extremely resistant parasites that don’t respond well to current drugs.

To some degree in human populations, education can help curtail additional infections. If people are trained about careful handwashing and avoiding sources of infection like untreated or fresh water, the number of parasitic infection can be reduced. This is more difficult in animal populations because animals may have repeated access to sources of infection like contaminated grass and fecal matter, and they are often housed together where infection can easily spread.

This is one thing doctors emphasize when they treat people with an anthelmintic. The person is only effectively treated if he doesn’t reinfect himself or other members of his household. Proper hygiene, especially when using the bathroom and during food preparation, is typically key to making certain an infection doesn’t remain.

Given the varying types of anthelmintics, it’s usually difficult to speak to side effects. These may be different and parasite type may determine length of dosage and other medical instructions. Some common side effects can include things like stomach upset, but this doesn’t occur in all people.