Chemotherapy of Trematode and Cestode Infections
About this topic
This specialized parasitology topic is designed for advanced tertiary students in Zambia studying biomedical sciences or tropical medicine. It covers the pharmacology of drugs used against flukes (trematodes) and tapeworms (cestodes). The module focuses on Praziquantel as the drug of choice for most trematode infections (e.g., schistosomiasis) and its mechanism involving increased calcium permeability leading to parasite paralysis. For cestode infections, it details the use of Albendazole and Niclosamide, explaining their actions on parasite glucose uptake and microtubule function. Key therapeutic applications such as treating neurocysticercosis and hydatid disease are emphasized. For Zambian learners, understanding these treatments is vital, as diseases like schistosomiasis are endemic, and managing complex parasitic infections requires precise pharmacological knowledge for successful patient outcomes and national disease control programs.
What you'll practise (21 questions)
- Praziquantel is effective against both adult schistosomes and their larval forms (cercariae). True or False?
- Which drug is commonly used to treat balantidiasis?
- What is the recommended first-line treatment for giardiasis in many settings?
- The drug Quinacrine (Atabrine) is an alternative treatment for giardiasis.
- The drug Furazolidone is an alternative treatment option for giardiasis.
- What is the mainstay of treatment for balantidiasis?
- The drug Iodoquinol is effective against the trophozoite stage of Entamoeba histolytica but has no activity against Giardia lamblia.
- The drug Nitazoxanide is an effective broad-spectrum antiparasitic agent that works against Giardia lamblia but has no effect on Cryptosporidium parvum.
- The drug Atovaquone is a first-line treatment for Pneumocystis jirovecii pneumonia and has some activity against Toxoplasma gondii, but it is not effective against Giardia.
- The drug Paromomycin is a luminal amebicide that is also effective against Giardia lamblia and is considered safe in pregnancy.
- Which of the following statements best describes the primary mode of action of the drug Ivermectin?
- The drug Albendazole is effective against Giardia lamblia, making it a useful alternative to metronidazole.
- The drug Quinacrine (Atabrine) is still widely used as a first-line treatment for giardiasis due to its excellent safety profile.
- The drug Nitazoxanide is only effective against anaerobic protozoa and has no activity against helminths.
- Which of the following anti-protozoal drugs works by inhibiting the enzyme dihydrofolate reductase (DHFR)?
- A patient presents with severe, watery diarrhea for 2 weeks, weight loss, and bloating. Stool antigen test is positive for Giardia. The patient reports an allergy to metronidazole (causing severe nausea). What is the most appropriate alternative treatment?
- The drug Clotrimazole, commonly used as a topical antifungal, is also a first-line treatment for trichomoniasis.
- Which of the following best describes the mechanism of action of the anti-malarial drug Artemisinin?
- Which of the following best describes the mechanism by which Praziquantel exerts its effect on cestodes (tapeworms) and trematodes (flukes)?
- Which of the following best describes the mechanism by which Albendazole exerts its anthelmintic effect?
- The drug Mebendazole has a broad spectrum of activity against intestinal nematodes but is also highly effective against Giardia lamblia.
Answer each question above to see the correct answer and a full explanation.