Where is the information that a pH of <7.0 is required coming from? I find the comment on a few other fish sites but the wording tends to make me think it came from the levamisole thread here.
Many other fish sites that discuss Levamisole make no mention of that requirement. Nor do the endless studies i have reviewed. Many of which mention environmental pH in the 7's and 8's. But, those studies were using Levamisole as a food additive or injectible. I believe a freshwater fish has a blood pH of approximately 7.7. Product data sheets even provide a pH range of a 1% aqueous solution of Levamisole Hydrochloride as 6-8.
Help please. it is vexing me--lol.
Hmm,... why is it even interesting?sully wrote:Where is the information that a pH of <7.0 is required coming from?
pH<7.0 is an urban legend, that seems to go back decades. It would be very difficult to track it into the pre-Internet antiquity.
OK, here is how you can approach it: there was an article on Levamisole in a May issue of some popular fish magazine. Get in touch with the authors, they seem to know the history a bit (I have the magazine somewhere in this room..but cannot see it offhand).
off and on over the past several years i have tried to post helpful advice to people having issues with fish health at this site--not so much since the new skin came into being.
I do post substantially more at other sites--more generalized sites.
I like to be accurate when i offer advice. And, today the question came up somewhere else with a "quote" from a very old thread here that called into question what i was suggesting.....
I think several people here have gotten to know me well enough (through this site, one or two others, and even a recent chance meeting in an lfs in my hometown--hope the presentation went well Jim) over the years to understand that it is not a question with any intent other than that which is stated, i am a curious man by nature. i have a lot of respect for the incredible knowledge many of the old timers and regulars here possess. I was hoping that if i missed something they could help me fill in a blank. it is sometimes easiest to go to the source when looking for a reference to information.
i guess i will try harder to create a more obvious and compelling "interesting" factor next time i wonder about something. i always thought information in the pursuit of knowledge was "interesting" enough. is the "interesting" factor a new way to grade queries here? obviously it was interesting enough to get mikev to pad his post count. now if we could achieve some specificity in response the post would be that much better.
mikev, pick someone else to patronize.
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The protocols for levamisole treatment on fish were largely developed by Dr Momfish right here in Toronto. I'm not sure where she got the <7.0 figure from.
As she seldom monitors this forum, I'll ask her and see if she can post some info.
I do know that the pH factor seems less critical than was once supposed.
Study of stability of Levamisole (for use in humans) found this:
I'll look a bit more after class because I'd like to see some definitive answer to this issue myself. I am sure that I found the information before when working on the book but based on the link above the information seems to be saying that it does break down significantly as the pH rises...Like temperature of storage, pH had an impact on the chemical stability of levamisole. It was shown that the rate of decomposition of levamisole rapidly increased between pH 5 and 7 and at pH 8 it was about seventy times faster than at pH 2 (9-11). Excipients and pH of solutions prepared from tablets could probably explain the difference in stability. Thus, the use of the solution prepared from powder would be preferable in practice.
Found plenty of sites discussing levamisole. None definitively state whether or not pH is an issue. Even the soluable powdered from that is added to drinking water makes no mention of pH issues. Plowed through what papers were available without fees, only to find little to no references to pH reactivity of levamisole.
Went looking at manufacturers sites. Humbug. Lots of sales pitching and not much specifics.
Finally caved and emailed to Jack Bain at Animalmedics.com in the UK to see if he could connect me with the manufacturers of the stuff they sell for any kind of test results, parameters, ANTHING that would indicate a specific range of pH being required.
Have a call in to IVX Animal health tech support vets to see if they have any info. Meanwhile, I do remember that at one point in the book work I had found research that clearly said that it was ok to use above 7.0. Can I find it? No. The bookmark is gone.
If I wasn't such a natural born PITA I'd hang it up...
http://www.alibaba.com/catalog/11099877 ... ablet.html
I'm still looking...Levamisole hydrochloride is a white to almost white crystalline powder which is almost odorless and is freely soluble in water. It is quite stable in acid aqueous media but hydrolyzes in alkaline or neutral solutions. It has a molecular weight of 240.75.
http://www.chemicalland21.com/lifescien ... LORIDE.htm
It also says:
Looking into that site a little I'm not so sure just how reliable it is...The hydrochloride salt of levamisole is a white crystalline powder with odorless; soluble in water and methanol; slightly soluble in ethanol and methylene chloride; insoluble in ether; stable in acid aqueous media but hydrolyzes in alkaline (or neutral) solutions.
So far, I am not finding anything to justify its efficacy at pH above 6.9.
I call Schering-Plough to ask their tech support about the product. Whiney, young female, "Well, we didn't have to do any of that kind of testing...we would have gotten complaints by now if it was a problem. . . I can't give you that kind of proprietary information..." blah blah blah. Dead end there. Now who feels patronized?????!
Meanwhile, chemically, it still sounds like cooler acid water is the best medium for its use. Anecdotally? Well, " Your mileage may vary..."
funny how when we put a bit of effort into something we think might be important we can feel a bit patronized when others do not sense the significance of an answer.
you are great. I said thanks in the other thread on the topic. cannot say it enough.
so many people out in the fishworld confronted with conflicting and sometimes erroneous answers simply trying to do what is best for their fish. They feel bad enough that they cannot adequately tend to the lives for which they have taken resposibility. And then they start getting spun like a top with answers to what seem like such simple questions. Out of frustration, confusion, and the strong desire to do something to help their sick and dying fish, they do something with fatal or no result. Or, they are forced into a position of "rolling the dice"--just doing something, even if the something is nothing--often wondering as a result if they are responsible for killing their finned friends.
It may seem small, but the relatively simple answer, from a responsible source, is a helpful tool in making sure that various therapies for disease resolution can be quickly and accurately discussed throughout the hobby.
Thanks! i am sure you understand how many forums across the web get bogged down with this discussion. Hopefully the definitive answer will allow a better understanding permitting a more adequate response in helping sick fish. and the stressed out fishkeepers--lol.
just a random, parting thought to the thread--maybe update the internal parasite archive? http://loaches.com/faq_parasites.html
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