Trematocides (Praziquantel) and Cestodicides (Niclosamide) – Antihelmintic Drugs

00:00 Let's move on to the trematodes.

00:03 So the trematodicidal agents are -- the prototypical one is praziquantel.

00:09 It increases the membrane permeability to calcium of the organism.

00:14 Which results in a marked contraction of the trematode and then paralysis.

00:19 It's used in trematode and cestode infections.

00:23 And it is the drug of choice in schisotosomiasis.

00:27 It's an alternative to albendazole in systemic cysticercosis or the pork tapeworm.

00:34 And it is contraindicated in ocular cysticercosis.

00:39 So ocular cysticercosis, you must treat with albendazole.

00:43 So here's an example of ocular cysticercosis or pork tapeworm.

00:49 I'm going to say pork tapeworm because it's easier to say.

00:51 So I'm going to say it again and again.

00:53 Pork tapeworm, ocular treat with albendazole.

00:57 Systemic you can use praziquantel.

01:02 In terms of the mechanism of action of praziquantel, it increases the membrane permeability to calcium as well.

01:08 And it causes the mark contraction and then paralysis of the agent.

01:12 Toxicity includes headache, dizziness and drowsiness.

01:16 Let's move on to the cestodes.

01:19 So the cestodicidal agents are quite very -- I think I'll talk quickly about niclosamide.

01:28 So niclosamide is interesting because it works differently then the other agents.

01:33 It uncouples the oxidative phosphorylation.

01:37 This cause paralysis of the organisms.

01:40 And it activates ATPases in the tapeworm.

01:43 It is an alternative drug in beef, pork and fish tapeworms.

01:47 But is not useful in systemic cysticercosis or pork tapeworm cysts.

01:53 Now here is an image of cystic cysticercosis.

02:00 You can see the cysts present in the liver on the CT scan.

02:03 And it is pointed out to you with a white arrow.

02:07 The ova and larva are not killed by niclosamide.

02:12 Use albendazole in the cyst form of pork tapeworm.

02:19 In terms of the toxicity of niclosamide, gastrointestinal distress, headache, rash and fever.