Antiparasitics

Question 1

Albendazole

Answer 1

• Antihelminthic – Benzimidazole (well absorbed with fatty meal)
• Bind tubulin, inhibit glucose uptake
• Contraindicated in pregnancy
• Intesetinal helminthes, cestode larval cyst – usually single dose

Question 2

Mebendazole

Answer 2

• Antihelminthic – Benzimidazole (poorly absorbed)
• Bind tubulin, inhibit glucose uptake
• Intestinal helminths

Question 3

Ivermectin

Answer 3

• Antifilarial - Benzimidazole
• Cl-currents (side spectrum of activity) – serum half life is 12 hours (give single dose)
• Fewer adverse reactions
• Broad spectrum (Onhocerciasis, W. bancrofti, B. malayi, L. loa, Strongyloids stercoralis)

Question 4

Praziquantel

Answer 4

• Antifilarial - Benzimidazole
• Visual damage to worm surface, Ca release from endogeneous stores, worm paralysis and death
• Adult tapeworms and cestode larval cysts, active against all trematodes (except one)

Question 5

Artemether-lumefantrine

Answer 5

• Anti-malarial
• Combination doxycycline/quinine – prophylaxis treatment
• Abdominal pain, nausea, vomiting, headache
• CQ-resistant P. falciparum, P. vivax, and other species – active against hypnozoites tage

Question 6

Chloroquine

Answer 6

• Anti-malarial
• Active against digestive vesicles of asexual intraerythrocytic stage
• Drug of choice for P. vivax, P. ovale, P. malariae, CQ sensitive P. falciparum

Question 7

Mefloquine

Answer 7

• Anti-malarial
• Active against all plasmodium species – half life 14 days (good for prophylaxis – once a week)
• Neuropsychiatric reactions
• CQ-resistant P. falciparum

Question 8

Metronidazole

Answer 8

• Anti-protozoal
• Interacts with DNA and other cellular constituents
• Protozoa living in anaerobic environments (Giardia, Trichomonas)

Question 9

Nitazoxanide

Answer 9

• Anti-protozoal
• Ferredoxin oxidoreductase
• Anaerobic protozoa and bacteria – Cryptosporidium parvum, Giardia lamblia