How Do Antiparasitic Agents Work?

Antiparasitic agents are a class of medications used in the management and treatment of parasitic diseases, such as those caused by helminths, amoeba, parasitic fungi, protozoa, and ectoparasites. Parasites are microorganisms that live on or inside another organism known as the host organism and benefit at the expense of their host organism. Antiparasitic agents do not work for viral infections such as the common cold and flu.

Antiparasitics are one of the antimicrobial drugs which can include the following:

• Protozoa: unicellular organisms, particularly high propensity to infect immunocompromised patients such as those with acquired immune deficiency syndrome
• Helminths: parasitic worms, transmitted via accidental ingestion, skin penetration, or a vector bite
• Ectoparasites: organisms that live externally on the skin of hosts. They include mites, fleas, ticks, lice, and bedbugs.
• These are administered orally as a tablet and a suspension (liquid).

Antiparasitic agents work in the following ways:

• They work by stopping the growth of certain bacteria and parasites.
• In addition, they eventually kill the invading parasites.

Antiparasitic agents are used in conditions such as:

• Amebiasis (an infection of the intestine that can cause diarrhea, gas, and stomach cramps and can spread to other organs such as the liver)
• An amebic liver abscess (collection of pus in the liver in response to an intestinal parasite called Entamoeba histolytica)
• Head lice
• Diarrhea caused by Cryptosporidium parvum or Giardia lamblia
• Chagas disease (also known as American Trypanosomiasis, an inflammatory, infectious disease caused by the parasite Trypanosoma cruzi)
• Toxoplasmosis (a disease that results from infection with Toxoplasma gondii parasite)
• Giardiasis (an infection of the intestine that can cause diarrhea, gas, and stomach cramps)
• Bacterial vaginosis (an infection caused by an overgrowth of harmful bacteria in the vagina)
• Trichomoniasis (a sexually transmitted disease that can affect men and women)
• Tay-Sachs & Sandhoff disease (inherited disorders of metabolism, caused by hexosaminidase deficiency that causes severe neurologic symptoms and early death)
• Hepatic coma (a decline in brain function that occurs because of liver disease)
• Dientamoeba fragilis (a parasite that lives in the large intestine of humans)
• Tapeworm infection (flatworms that can live in the intestines)
• Cutaneous leishmaniasis (a skin infection caused by a single-celled parasite that is transmitted by the bite of a phlebotomine sand fly)

Common side effects include:

• Diarrhea
• Nausea
• Vomiting
• Abdominal pain
• Anorexia (lack or loss of appetite)
• Flatulence (gas)
• Headache
• Unpleasant metallic taste

Other rare side effects include:

Dizziness (feeling faint, weak, or unsteady)

• Tinnitus (ringing or other noises in one or both ears)
• Allergic reactions such as rash/hives and itching
• Urine discoloration
• Muscle weakness
• Abnormal liver function test
• Leukopenia (reduced number of white blood cells)
• Numbness or tingling of hands or feet
• Visual impairment

Information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Drug names include:

• Alinia
• Benznidazole
• Daraprim
• Humatin
• Lodoquinol
• Mineral oil topical
• Nitazoxanide
• Nix Ultra Shampoo
• Paromomycin
• Pyrimethamine
• Tindamax
• Tinidazole
• Yodoxin