What are antiparasitic medicines?

Antiparasitic medicines are specialised drugs used to treat infections caused by parasites—organisms that live on or inside a host and depend on it for survival. Parasites can infect various parts of the body, including the intestines, blood, skin, and internal organs, leading to a wide range of diseases.

How Do Antiparasitic Medicines Work?

Antiparasitic drugs help the body get rid of infections by either killing parasites or stopping them from growing and reproducing. How they work depends on the type of drug and the parasite they target. For instance, some drugs mess with how the parasite gets energy, some disrupt its nervous system, and others prevent it from reproducing.

Types of Parasites Treated by Antiparasitics

• Protozoa: Single-celled organisms that lead to illnesses such as malaria, giardiasis, and amoebiasis.
• Helminths: Parasitic worms like roundworms, tapeworms, and flukes often impact the digestive system and other parts of the body.
• Ectoparasites: Parasites from outside, like lice and mites, that lead to skin infections.

Common Antiparasitic Medicines

• Antiprotozoals: Treat protozoan infections. Examples include metronidazole, chloroquine, and artemisinin-based drugs.
• Antihelminthics: Target parasitic worms. Examples include albendazole, mebendazole, ivermectin, and praziquantel.
• Ectoparasiticides: Topical treatments for skin parasites such as permethrin and malathion.

Conditions Treated

• Malaria
• Giardiasis and amoebiasis
• Ascariasis, hookworm, and other worm infections
• Tapeworm infestations
• Scabies and lice infestations

Safety and Precautions

Antiparasitic medicines are generally safe when used as prescribed, but they can cause side effects including nausea, headache, dizziness, diarrhea, rash, and abdominal discomfort. Some antiparasitic drugs may lead to more severe adverse effects like neurotoxicity, liver toxicity, or allergic reactions, especially when taken improperly or for prolonged periods.​

Common side effects include:

• Gastrointestinal symptoms (nausea, vomiting, diarrhea, abdominal pain)
• Dizziness and headaches
• Skin reactions (rash, itching, pruritis)
• Fatigue and weakness

Rare but serious side effects can include:

• Kidney or liver damage
• Neurological symptoms (seizures, hallucinations)
• Blood disorders (leukopenia, agranulocytosis)

It's essential to follow your healthcare provider's instructions carefully and complete the full course of treatment to effectively eradicate parasites and minimise drug resistance.

People with certain conditions, such as kidney disease, liver problems, or those who are pregnant or breastfeeding, should consult their healthcare provider before taking antiparasitic medications.

Regular monitoring during treatment may be needed to detect and manage any adverse effects promptly.​