reaction to levamisole

[grelot]

I treated a pair of discus for capillarias with levamisole in the water 4 days ago. Since then the are acting very nervous. I saw them freaking out and smashing themselves everywhere in the tank twice in two days.

Is this something you have also observed when treating with it???

[kaceyo]

I've treated with it a few times and haven't had any negative reactions. In fact, just the opposite. They act less nervous and more outgoing. You are supposed to be able to overdose up to ten times the recommended dose w/out problems. What dose and form of levamisol did you use.

Kacey

[April]

where did you find it in canada?

[Diamond Discus]

I had problems with it when I tried it with my discus, and had to remove the levamisole with 2 high volume water changes within the first hour of adding it to the tank. It took the Discus a few days to get back to normal again....they became dark, lethargic, hiding low in the corners of the tank while rapidy gilling. I was shocked because I had used this as a standard course of treatment for any fish I purchased with excellent results.

[brewmaster15]

not always....but Its possible that fish exhibiting stress or other "side effects " to the dewormer may be doing so because they have worms.

-al

[forrest]

hi,
in my opinion.different fishes sometime have different reaction to the same med,even same dosages.i take PP as an example,a fish that carrying heavy problem on the gill cant really stand for PP even to half of the dosage as we normally using,it has to start from maybe 20-30% of the dosage of PP we normally use.im not very sure about the levamisole(or maybe it has another name over in we i live).i think it could be the fishes may have some problem which cos the fishes react weird.

rgds,
forrest.

[Hans Kloss]

Levamisole may be toxic if used in basic water. With pH below 6.5 it is relatively safe and efficient in concentration of 10 ppm. But IMO the best and safest method is oral administration of levamisole with food. I stopped to use it because it is completely inactive against flatworms, flukes etc.
Hans

[brewmaster15]

Hi Hans,

Levamisole may be toxic if used in basic water. With pH below 6.5 it is relatively safe and efficient in concentration 10 ppm. Where did you find this info?
The recommended dose for this medication in the USA is 2ppm, and pH isn't an issue thats mentioned in any of the journels, not that its not possible.

For what its worth ...I've used it as high as pH 7.8 on many discus with no incident.

-al

[ShinShin]

I have never had a problem wth levamisole either. I use a dosage of 1mg/L of tank water.

Mat

[Hans Kloss]

Hi Hans,
Where did you find this info?

In my own tanks and also in tanks of my friends. There were noticed similar examples of fish poisoning in basic water, maybe due to instability of free base in aquarium conditions.


The recommended dose for this medication in the USA is 2ppm, and pH isn't an issue thats mentioned in any of the journels, not that its not possible.


There is a lot information on the net about levamisole toxicity in basic water, for safety and efficient dosage see for example:
http://www.skepticalaquarist.com/docs/health/othmed.shtml
http://okcaa.org/articles/disease.html
10 ppm dosage was established ONLY for acidic water and may be risky for scaleless fish.



For what its worth ...I've used it as high as pH 7.8 on many discus with no incident.


There is very interesting overview of levamisole usage at Loaches Online web site:
http://www.loaches.com/Members/shari2/levamisole-hydrochloride-1

Its author also advocates for 2ppm dosage and neglects the necessity of pH diminishing. It works quite fine for him but....
READ CAREFULLY ALL COMMENTARIES below this article.
I've seen with my own eyes similar levamisole massacre (with 2ppm dosage!) and never heard about toxic effect if pH was properly adjusted. This drug is NOT safe for sure.
Hans

[brewmaster15]

Hans,
from the link you posted...

http://www.loaches.com/disease-treatment/levamisole-hydrochloride-1

De-bunking a common misunderstanding about Levamisole HCl.



Does Levamisole HCl require a pH of below 7.0 to be effective?

In a word, NO.


This common misconception regarding the uselessness of Levamisole HCl in higher pH water needed a definitive answer.

Let's apply some common sense. When we look around at the other uses of Levamisole HCl we find that one common formulation is administered by adding it to livestock drinking water. Are all water supplies the same? It seemed unlikely to me that among all the farms using this medication every water supply would have a pH below 7.0.

After some digging around all over the Internet and phone calls to various Veterinarians and chemical companies the answer I was given by Dr. Hal Sinclair of IVX Animal Health (http://www.psiqv.com/support.aspx) was both clear and simple. Levamisole base (C11H12N2S) is unstable in water and will degrade rapidly as pH levels increase. Levamisole HCl will not. It's the addition of the hydrochloride molecule that makes the difference.
Levamisole HCl is stable in water for up to 90 days and will do its job in aquaria with with both low and high pH values.
Taking the space to go through all this chemistry may be more than you want to know. However, chemistry plays a large role in fishkeeping. It helps to be somewhat comfortable with the basics to comprehend the Nitrogen cycle and to balance the aquatic environments in which our fish live. Planted tank gurus, especially, spend time understanding the chemistry of their tanks for both fish and plant benefit.

Chemistry has already helped us to answer the pH question which has been plaguing the community for years. We will need it again in order to determine effective dosing of Levamisole HCl to cure our fish. Knowing the chemical formula, the molecular weight, and the specific gravity of the molecule will give us the information we need to make some calculations that will help us to do just that.


From your link it appears that it is neither Toxic at a higher pH nor is ineffective as stated in this the skeptical Aq.article.. IF its in its HCL form...which is what we use in the USA.....

I don't doubt it may have toxic effects on some species of fish and theres definetly concerns about the "base" form...but I can only share with you my experiences using the tramisole...which is levamisole HCL.

Hth,
al

[Hans Kloss]

Levamisole base (C11H12N2S) is unstable in water and will degrade rapidly as pH levels increase. Levamisole HCl will not. It's the addition of the hydrochloride molecule that makes the difference. Levamisole HCl is stable in water for up to 90 days and will do its job in aquaria with with both low and high pH values.


Above statement in quite non sense from the chemical point of view. Pure levamisole base should rapidly liberate from its HCl salt in basic pH. It is common behavior of almost all HCl salts of amines, until amine is not so called "proton sponge".



From your link it appears that it is neither Toxic at a higher pH nor is ineffective as stated in this the skeptical Aq.article..


But there is much more important instance- experience of fish keepers. About 10% of them have noticed fish intoxication when levamisole was used in basic water. On this forum we have found 3 persons (including myself) which can claim toxic effect of this drug for discus.



IF its in its HCL form...which is what we use in the USA.....

Levamisole is used worldwide as its salt with HCl or phosphoric acid.



but I can only share with you my experiences using the tramisole...which is levamisole HCL.


Just like all of us. I've used levamisole during 2 years, often with high pH and noticed acute fish intoxication only once.
For me it is enough to consider this drug as not very safe if used in basic water.
So, if somebody will start first time with levamisole I should recommend to be prepared for immediately fish rescuing with massive WC and suggest next try after a week or two with low pH and dosage increased. It works quite fine not only for me.
Hans

[brewmaster15]

Hans,

I don't know what to tell you here...I'm not a chemist.. But that site you linked gives chemistry info and documents it. It seems very well researched. .. IF you feel their info is inaccurate...I'd suggest contacting them.. or contacting the source of their info to dispute it.

I do have another question for you though......


But there is much more important instance- experience of fish keepers. About 10% of them have noticed fish intoxication when levamisole was used in basic water. On this forum we have found 3 persons (including myself) which can claim toxic effect of this drug for discus.
where did this 10% statistic come from ?

-al

[Hans Kloss]

I do have another question for you though......
where did this 10% statistic come from ?


It comes from my private contacts with fish keepers, including experienced discus breeders and sellers. Some of them reported water becomes slightly cloudy shortly after drug addition.
Hans

[tonymaccs]

I did a lot of internet reading on levamisoleHCl when I was intending to try a proprietary livestock medication that contains prazi and levamisole. I was concerned as the levamisole/prazi ratio was 2:1 and the resultant levamisole concentration would be as high as 4 ppm.
At the time I came across the above quoted article and I recall it saying Lev is also effective/usefull at pH above 7.0. I think this is different to the question of whether it might be harmful to discus specific at pH above 7.0.
I dont recall coming across any information confirming or promoting this potential harm, but it is worth keeping caution in mind.
I did start using the combined medication and have eventually come to use it with confidence as the only side effect noticed (in only a small portion of those treated) was loss of appetite and a general slowing down which rectified itself after a few days.
I dont have any tanks with pH above 7.0 so no direct experience.
Tony