Questions – Antiprotozoal and Anthelmintic Drugs

00:00 Okay, let's take a look at a question here.

00:04 The President returns from a first trip to Cuba.

00:08 First time a president has visited Cuba in 50 years.

00:12 He presents with fevers, dehydration and nausea.

00:14 A blood smear shows plasmodium falciparum schizonts.

00:18 The following drugs are schizonticides except: Choloroquine dihydroarteminisin Quinine Halofantrine Sulfonamides You chose halofantrine.

00:40 Which drug would be effective in treating amebiasis in the liver? Diloxanide furoate Iodoquinol Paromomycin Metronidazole Good, you chose metronidazole.

01:03 So remember metronidazole is particularly effective in systemic infection and it's effective in the liver.

01:09 And we treat severe intestinal infections and liver abscess is the same with respect to amoeba type infections.

01:20 The principle behind amebicidal therapy is understanding where each drug works.

01:25 The first three drugs are luminal amebicides.

01:29 They stay in the lumen of the gut and work very well there.

01:32 If the infestation is at the luminal surface that is.

01:35 Once the organism becomes systemic, metronidazole would be the logical choice.

01:40 As it's activated by anaerobes and it's very, very effective in hepatic tissues.

01:48 While on mission with Medecins sans Frontieres or Doctors without Borders, you see a young boy with a strange lump in his retina.

01:56 It is a small cyst with a hard center.

02:06 What would be the appropriate treatment for that finding? Niclosamide Praziquantel Mebendazole Albendazole.

02:18 Good, you chose aldbendazole.

02:19 So the image is a typical presentation of retinal cysticercosis.

02:25 The larval stage of pork tapeworm.

02:28 Niclosamide does not kill pork tapeworm in this stage.

02:32 It only kills it in the cestode stage.

02:35 Praziquantel should never be used in ocular cysticercosis because the destruction of the organism can actually cause permanent ocular lesions.

02:46 Mebendazole is not systemically absorbed to any great a deal any great degree and it's therefore not a great choice.

02:54 Albendazole is the drug of choice in ocular cysticercosis.

03:00 That's it.

03:02 You made it through this lecture.

03:03 You did really well.

03:05 I'm glad to say that nobody got sick looking at these wonderful pictures.

03:09 And you made it through our pharmacology lecture.

03:10 So kudos to you.

03:12 Go write your exam.

03:13 Show them what you know.