Anthelminthics

Anthelminthics

Anthelminthics, also known as antihelminthics, are a class of drugs used to treat infections caused by helminths, which are parasitic worms. These drugs are essential in the management of diseases caused by various types of helminths, including nematodes (roundworms), cestodes (tapeworms), and trematodes (flukes). Anthelminthics work by either killing the parasites or expelling them from the host's body.

Mechanism of Action

Anthelminthics can act through several mechanisms to eliminate parasitic worms:

• Neuromuscular Blockade: Some anthelminthics, such as piperazine, cause paralysis of the worms by blocking neuromuscular transmission, leading to their expulsion from the host.
• Inhibition of Metabolic Processes: Drugs like albendazole and mebendazole inhibit the uptake of glucose by the parasites, depleting their energy stores and leading to their death.
• Disruption of Cellular Structures: Praziquantel, for example, increases the permeability of the cell membranes of schistosomes, leading to their disintegration.

Common Anthelminthic Drugs

• Albendazole: Effective against a wide range of helminths, including Ascaris lumbricoides, Trichuris trichiura, and hookworms.
• Mebendazole: Similar to albendazole, used for treating infections by nematodes.
• Praziquantel: Primarily used for treating trematode and cestode infections, such as schistosomiasis and tapeworm infections.
• Ivermectin: Used for treating infections caused by nematodes, such as Onchocerca volvulus (river blindness) and Strongyloides stercoralis.

Clinical Use

Anthelminthics are used in both human and veterinary medicine. In humans, they are prescribed based on the type of helminth infection diagnosed. Diagnosis is typically confirmed through stool examination, serological tests, or imaging studies.

In veterinary medicine, anthelminthics are used to treat parasitic infections in livestock and pets, which can improve animal health and productivity.

Side Effects

While generally safe, anthelminthics can cause side effects, which may include:

• Gastrointestinal disturbances (nausea, vomiting, diarrhea)
• Headache and dizziness
• Allergic reactions

Resistance

Resistance to anthelminthics is an emerging problem, particularly in veterinary medicine. Overuse and misuse of these drugs can lead to the development of resistant strains of parasites, making infections harder to treat.

Also see

• Parasitic worm
• Helminthiasis
• Antiparasitic drug
• Infectious disease

Classification