API General Cure

[Humblefish]

API General Cure is an interesting medication, as it contains both praziquantel and metronidazole. Prazi is widely used to treat gill flukes and some internal parasites, whereas metro is good at eradicating all internal parasites... even the ones prazi doesn't treat. So, you can see how useful it is to have both active ingredients in one medication.

Metro is easily water-soluble, but prazi is not. So I've been wondering just how the praziquantel found in General Cure works, being it's a powdered medication. Prazipro, the most widely used medication containing praziquantel, is a liquid that uses Oxybispropanol as an inert solubilizing agent. I've also read that powder praziquantel should be dissolved using a small amount of ethyl alcohol or even common vodka before dosing your tank (Oxybispropanol satisfies this requirement.)

I posed this question to Randy Holmes-Farley on this thread: https://www.reef2reef.com/forums/reef-chemistry-randy-holmes-farley/194677-praziquantel-water-soluble.html

I'm basically wanting to switch over from liquid Prazipro to a powder form of praziquantel. Like this: Praziquantel

The reason is I'm try to avoid the oxybispropanol found in Prazipro, which has caused bacterial blooms in my QT in the past - especially when mixed with other medications. I know powder praziquantel is "not easily water soluble", which is why it is suggested to mix it with a small amount of ethyl alcohol or even vodka.


But does that mean it flat out won't dissolve in water or it just takes a while to do so?

His response:

It is very poorly soluble in water. I doubt you can make a water only stock solution.

This begs the question: Exactly how is API implementing praziquantel in their General Cure powder? So, I called them. The first thing I wanted to clear up is exactly what is in General Cure. Because when I pull up General Cure's MSDS off their website it lists the following as ingredients: sodium chloride, metronidazole, trichlorfon, silica amorphous (fumed, crystalline free) and copper sulfate. They assured me that was the old formulation, and that the new one only contains praziquantel and metronidazole. They just haven't updated the MSDS yet.

My next question was how does their prazi work in powder only form? I was told that powder praziquantel is a "contact pesticide" which does fully dissolve in water; it just takes longer if you don't use ethyl alcohol to mix it with. I was also told that General Cure can be safely mixed with just about any other fish medication, including Chloroquine phosphate. I will be testing that out soon, probably on a damsel.

So there you have it. I'm not 100% sure what to think, really. I'm still processing everything. Please discuss below!

 

[Randy Holmes-Farley Verified Community Expert]

FWIW, it is the case for many drugs that you can dissolve enough through the water (and natural surfactants/soaps) of the whole human body to have a biologically useful effect, but not enough to dissolve all of that same amount of drug in a teaspoon of water that you'd drink it in.

 

[Humblefish]

FWIW, it is the case for many drugs that you can dissolve enough through the water (and natural surfactants/soaps) of the whole human body to have a biologically useful effect, but not enough to dissolve all of that same amount of drug in a teaspoon of water that you'd drink it in.

So, are you saying if I took 75 mg (for example) of Praziquantel and tried to dissolve it in 1 liter of water, in order to make up a solution, it probably wouldn't work?

However, if I took that same 75 mg of prazi and dumped it in a 10 gal QT, it would eventually dissolve because the amount of water is greater? It both cases without using ethyl alcohol (or similar) to dissolve the powder form of prazi.

 

[Humblefish]

Bump Randy Holmes-Farley

Would love your input on the above. Is my reasoning sound or am I completely off base here?

 

[mrukus]

Following.... so would it also be recomended to does general cure 2x 5 days apart like prazi?

 

[Humblefish]

Following.... so would it also be recomended to does general cure 2x 5 days apart like prazi?

Assuming powder praziquantel can be dissolved in a large body of water (at least 10 gallons), then yes. General Cure also contains metronidazole, which is easily water soluble and treats internal/intestinal parasites. So there's that added benefit. The last time I used General Cure, I waited 7 full days from the start of the first treatment to do the second round. Reason being is because one round of General Cure is spread out over two doses (see directions below), so you are still hitting the fish with the second round 5 days after the second dosage.

Directions for Use: For best results, remove activated carbon or filter cartridge from filter and continue aeration. For each 10 gallons (38 L) of water, empty one packet directly into aquarium. Repeat dose after 48 hours. Wait another 48 hours then change 25% of the aquarium water and add fresh activated carbon or replace filter cartridge.

 

[Randy Holmes-Farley Verified Community Expert]

So, are you saying if I took 75 mg (for example) of Praziquantel and tried to dissolve it in 1 liter of water, in order to make up a solution, it probably wouldn't work?

However, if I took that same 75 mg of prazi and dumped it in a 10 gal QT, it would eventually dissolve because the amount of water is greater? It both cases without using ethyl alcohol (or similar) to dissolve the powder form of prazi.

That's the idea, although I cannot be sure of the exact amounts that will dissolve.

Dissolving it first in a solvent like ethanol then adding to water can really speed the process tremendously.

 

[Humblefish]

That's the idea, although I cannot be sure of the exact amounts that will dissolve.

Dissolving it first in a solvent like ethanol then adding to water can really speed the process tremendously.

Thank you, Randy. I've used General Cure in the past, and I could smell the praziquantel in the water for days afterwards. I realize that doesn't necessarily mean it all dissolved, but I also didn't see any powder on the bottom of the tank.

 

[Cment]

@Humblefish or Randy, do you recommend dissolving general cure first in ethanol or use as directed? If I choose to dissolve it first, how much ethanol would I need for 1 packet? Any complications seen in the fish if dissolved first? Would it degrade the metro since it cannot be separated?

 

[Humblefish]

@Humblefish or Randy, do you recommend dissolving general cure first in ethanol or use as directed? If I choose to dissolve it first, how much ethanol would I need for 1 packet? Any complications seen in the fish if dissolved first? Would it degrade the metro since it cannot be separated?

I personally don't like using ethanol as it can cause problems if you suddenly need to dose another medication into the water.

I've experimented with a few different things for dissolving GC before dosing, but I think this suggestion I got from @stunreefer is working out the best: Place prazi into brine shrimp net, partially submerge, gently knead so fine particles drift out into the aquarium. Continue until all has been expressed into the water.

 

[Cment]

Thanks humble I'll give that a try!

 

[revhtree Verified Admin]

Interesting thread...

 

[stunreefer Verified Sponsor]

I agree with @Humblefish regarding the use of ethanol. I have also used Dimethyl sulfoxide (DMSO), used frequently in the koi world, which worked well and did not cause the same bacteria bloom observed with ethanol (vodka). However, some form of the brine shrimp net method is easiest and best method IME (I smash it into prefilter pads over high flow area of trickle filter).

 

[cmcoker]

@Humblefish
I dosed my wrasse in quarantine (currently in coppersafe) with general cure on February 27, per package I dosed again March 1st. I planned to start the second round 1 week from the 27th, bu midterms had me lose track of time and I have not started the second round yet.
So should I dose today, and in 48 hours. Then repeat starting next Thursday?

Hate I screwed that up as my little wrasse has only had decreased appetite during the general cure treatment

 

[Humblefish]

So should I dose today, and in 48 hours. Then repeat starting next Thursday?

Dose today and then again next Thursday (March 16). The 48 hrs later dosage is unnecessary.

 

[cmcoker]

Dose today and then again next Thursday (March 16). The 48 hrs later dosage is unnecessary.

Excellent, will do. Gonna feed him a bit extra before the dose goes in to tide him over

 

[blueface]

So I followed the directions on GC. Did the first dose waited 48 then second dose waited 48 then the WC. Are you guys saying I still need to do this again??

 

[cmcoker]

So I followed the directions on GC. Did the first dose waited 48 then second dose waited 48 then the WC. Are you guys saying I still need to do this again??

Yeah, believe it doesn't kill any eggs, so do it again in a week to kill anything that hatched

 

[melypr1985]

So I followed the directions on GC. Did the first dose waited 48 then second dose waited 48 then the WC. Are you guys saying I still need to do this again??

Pretty much. You only need to dose it once, then wait 5-7 days and dose it once more. The second dose 48 hours later is not needed each time.

 

[Humblefish]

I strongly recommend using GC in lieu of Prazipro on wrasses and other prazi sensitive fish. GC contains a more appropriate praziquantel dosage (2.0 mg/L); whereas Prazipro is slightly overdosed at 2.5 mg/L. Most fish should be able to handle this higher dosage, but it could be to blame for the deaths of wrasses and other sensitive species.