How Do Antiprotozoal Agents Work?

Antiprotozoal agents are a class of drugs used to treat infections caused by protozoa, which are single-cell organisms, belonging to a group of parasites. Protozoans typically are microscopic and similar to plants and animals as they are eukaryotes, thus having a clearly defined cell nucleus. Antiprotozoals are effective in treating diseases such as African Trypanosomiasis (sleeping sickness) and Chagas disease (an inflammatory, infectious disease caused by the parasite Trypanosoma cruzi).

African Trypanosomiasis (sleeping sickness) is caused by Trypanosoma brucei, transmitted by the tsetse fly and characterized by symptoms such as:

• Fever
• Severe headaches
• Irritability
• Extreme fatigue (tiredness)
• Swollen lymph nodes
• Aching muscles and joints
• Disturbed sleep patterns

Antiprotozoal drugs are prescription-only medicines and are available in various dosage forms such as tablets and capsules, usually taken three times a day with food. They are also available as a powder for preparing an injectable solution.

Antiprotozoal agents work in the following ways:

• Antiprotozoal agents destroy protozoa or inhibit their growth and ability to reproduce.
• They damage the protozoal DNA to limit the spread of infection.
• They inhibit a fundamental pathway of energy metabolism (inhibition of parasite dehydrogenase activity) in the protozoa, thus making them unable to grow and reproduce.

Antiprotozoal agents are used in conditions such as:

• African Trypanosomiasis (sleeping sickness)
• Chagas disease (caused by a parasite known as Trypanosoma cruzi, is a vector-transmitted disease affecting animals and humans, commonly known as American Trypanosomiasis)
• Refractory prostate cancer

Common side effects include:

• Diarrhea
• Nausea
• Vomiting
• Abdominal pain
• Anorexia (lack or loss of appetite)

Other rare side effects include:

• Dizziness (feeling faint, weak, or unsteady)
• Anemia (results from a lack of red blood cells)
• Leukopenia (reduced number of white blood cells)
• Thrombocytopenia (low blood platelet counts)
• Hypertension (high blood pressure)
• Heart damage
• Encephalopathy (damage or disease that affects the brain)
• Nerve pain in extremities
• Increased urination
• Shock (a life-threatening medical condition as a result of insufficient blood flow throughout the body)
• Optic atrophy (a condition that affects the optic nerve, which carries impulses from the eye to the brain)
• Kidney damage

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:

• Arsobal
• Eflornithine
• Lampit
• Melarsoprol
• Nifurtimox
• Ornidyl
• Suramin
• Suramin sodium