# oxfendazole vs fenbendazole & MOA



## Kapidolo Farms (Nov 28, 2012)

S. Giannetto & E. Brianti & G. Poglayen & C. Sorgi & G. Capelli & M. G. Pennisi & G. Coci, Efficacy of oxfendazole and fenbendazole against tortoise (Testudo hermanni) oxyurids, Parasitol Res (2007) 100:1069â€“1073

In this paper, I am glad to share, the authors suggest that both these compounds MOA is not directly against the worms within the GI, but rather from something in these compounds metabolized by the tortoise itself. They suggest oxfendazole is more effective too.

I have this understanding as they dose once for 100% efficacy, and by way of result show that after a die off off re-infection does not occur. 

Alternatively does the drug have an extended 'stay in the GI? 

Exactly how does the drug work? Does it kill the worm directly as if the GI is a tube, or does it get metabolized, and that makes the tube toxic?

If you know a paper I could read that would be a good answer. I am NOT seeking dosage advice.

Will


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## Yvonne G (Nov 29, 2012)

Can't help you, Will, as I've only ever heard of fenbendazole. Will be interesting to see if there's a paper we can read.


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## jaizei (Nov 29, 2012)

I do not have the answers you are looking for either, but that was an interesting paper.


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## yagyujubei (Nov 29, 2012)

http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/191507.htm
This may or may not help. From what I can understand, it seems these are pretty similar.


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## Kapidolo Farms (Nov 29, 2012)

Thanks so much, of course a moment of taking my own advice a 'googleing" would have gotten me there. But I am very glad for the kick in the . . .

So, it would seem that some aspect of the compounds are indeed metabolized when given orally as they also have some action against lung worms. It also has some direction action in the GI.

One thing I'd like to hear a vet comment on is the rate of passage in the GI track as an aspect of effectiveness. The Merck link suggest that slower gut transit time increases effectiveness, yet most times I have seen recommendations for the use of these compounds has been during high activity times of the year (warm tortoise). 

I wouldn't think to try and use it during hibernation, ever, but what about a cooler, yet still active time? Any vet care to comment.

Will


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## exoticsdr (Dec 4, 2012)

Will said:


> Thanks so much, of course a moment of taking my own advice a 'googleing" would have gotten me there. But I am very glad for the kick in the . . .
> 
> So, it would seem that some aspect of the compounds are indeed metabolized when given orally as they also have some action against lung worms. It also has some direction action in the GI.
> 
> ...



Will, as I understand...fenben (and oxyfen) both directly inhibit metabolic pathways and enzymes within the parasites. Fenben is poorly absorbed from the gut but that's not the case with oxyfen...that said, i've never used the oxyfen in reptiles so can't speak to its efficacy. Perhaps this question would be better posed to a veterinary pharmacologist, if you can find one, we general practitioners rarely delve that deeply into the minutia of the hows and why's of a drugs action...great question though and I too would be interested in hearing what you find out. Please feel free to email me your findings..Doc.


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