A group of drugs that is used to eradicate parasitic worm infestations
Anthelmintic drugs are used to eradicate worm (helminth) infestations of the intestine or of the tissues of other organs, such as the lungs. The most common intestinal worm infestation occurring in the UK is threadworm (see Threadworm infestation).
Infestations affecting the intestines are treated with anthelmintics that kill or paralyse the worms, which then pass out of the body in the faeces. Worm infestations of other body tissues are treated with anthelmintic drugs that circulate in the bloodstream and are absorbed by the tissues, where they kill the worms by preventing them from obtaining essential nutrients.
Many anthelmintic drugs are appropriate only for certain types of infestation. Your doctor will therefore need to identify the worm before prescribing the drug to be taken. In most cases, infestations are treated easily with a short course of oral drugs.
The most commonly used drug for intestinal infestations is mebendazole. Threadworms can often be eradicated with a single dose of mebendazole, provided that treatment is combined with good hygiene measures, such as careful handwashing, to prevent reinfestation. Your doctor may suggest that the whole family be treated with the drug at the same time, because threadworms can spread very rapidly to other people.
Worm infestations of the tissues, such as hydatid disease, which can affect the lungs, liver, or bones, may be treated with albendazole. Tissue infestations are difficult to eradicate, and it may be necessary to continue taking the drug for several weeks.
Anthelmintics usually do not cause side effects. However, sometimes the drugs produce diarrhoea, headaches, and dizziness. Albendazole may impair liver function; this may necessitate regular monitoring during treatment.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.