Metronidazole treatment question

[LizStreithorst]

Stir it in a bit of tank water before you dump it in the tank. It is slow to dissolve and will dissolve further once it's poured in.

[carlosf]

OK. I want to make it very clear that I am not attacking anyone on this thread, just the facts.


I have a PhD in organic chemistry, I've published articles in PNAS, JACS, ACIE and J. Med. Chem. as well as multiple patents. Three drugs I helped design are currently undergoing clinical trials. My current job is to design manufacturing processes for active pharmaceutical ingredients. I have personally done the experiment with much more sensitive molecules where aqueous solutions of a compound are stable indefinitely under indoor lighting but are 100% decomposed by mere seconds of exposure to daylight. My undergraduate research was focused on monitoring UV degradation of polypropylene. I can assure you that I am speaking with some authority on the subject.

Like Steve said, the paper you reference says that artificial light had no impact on metronidazole activity.

The UV/Vis spectrum of metronidazole is published: Special Topics and Reviews in Porous Media 5(4):361-367 and others.

In aqueous pH 6.8 phosphate buffer absorbance beyond 380 nm is noise (i.e. not absorbing). Published spectra of common LED and fluorescent grow lamps for aquarium use have no emission above 380 nm. For the same reason we can't see UV light, metronidazole can't be decomposed by visible light. For the same reason we don't get a sunburn from indoor lighting, metronidazole can't be decomposed by typical indoor lighting.

Manufacturers of metronidazole sell it in light proof containers to protect it from daylight.

Does turning off the aquarium light when treating with metronidazole hurt? No. Could leaving your aquarium light on during metronidazole treatment lead to failure? Also no. Should you try and block sunlight that hits your aquarium during metronidazole treatment? Probably Yes. Should you turn off the UV light? Also yes.

Hi James,

In what regards Metro, I prefer to give it on the food (Flagyl pill powder mixed into the food) to the fishes but of course if they don’t eat that will not work. I do it as prevention or as soon as I see any sign of white feces while they are still eating.
If the fishes don’t eat, Metro must be added to the water, there’s a lot of info about how to do it and usually it envolves dissolving a Metro pill (Flagyl or other) into the aquarium.
Given that aqueous solutions are available, the only reason I see for not being used more often is because they are not available for common people as pills are. Doctors and pharmaceuticals should have access to it but most people don’t.

This is reason why I’m quoting you:
I have an aqueous solution of Metro to be used as emergency if needed.
After reading this thread it seems Metro is sunlight sensitive and should be stored in light proof containers.
But… this aqueous solution is shipped in clear glass containers and the label doesn’t say anything about keeping it out of daylight!
This is the solution I’m talking about:
https://ukrstore.com/metronidazole-i...ronidazol.html

So, my question is:
Is this Metro aqueous solution safe and can be used, or Metro is decaying because of the non daylight-proof container?

Best regards

[brewmaster15]

Hi James,

In what regards Metro, I prefer to give it on the food (Flagyl pill powder mixed into the food) to the fishes but of course if they don’t eat that will not work. I do it as prevention or as soon as I see any sign of white feces while they are still eating.
If the fishes don’t eat, Metro must be added to the water, there’s a lot of info about how to do it and usually it envolves dissolving a Metro pill (Flagyl or other) into the aquarium.
Given that aqueous solutions are available, the only reason I see for not being used more often is because they are not available for common people as pills are. Doctors and pharmaceuticals should have access to it but most people don’t.

This is reason why I’m quoting you:
I have an aqueous solution of Metro to be used as emergency if needed.
After reading this thread it seems Metro is sunlight sensitive and should be stored in light proof containers.
But… this aqueous solution is shipped in clear glass containers and the label doesn’t say anything about keeping it out of daylight!
This is the solution I’m talking about:
https://ukrstore.com/metronidazole-i...ronidazol.html

So, my question is:
Is this Metro aqueous solution safe and can be used, or Metro is decaying because of the non daylight-proof container?

Best regards

Carlos that liquid you have is for injection only. Its also notbifba concentration that would be useful to treat a discus unless you had alot of those vials.

though not the same priduct mfg.. heres info from one in the USA.

Screenshot_20240519-101429.jpg

Screenshot_20240519-101556.jpg
these do say to protect from light..

[carlosf]

Carlos that liquid you have is for injection only. Its also notbifba concentration that would be useful to treat a discus unless you had alot of those vials.

though not the same priduct mfg.. heres info from one in the USA.

Screenshot_20240519-101429.jpg

Screenshot_20240519-101556.jpg
these do say to protect from light..

Yes, it is an injectable solution and in fact the quantity of Metro inside it (500mg) is not enough, at least for my aquarium . Some additional bottles would be required.

But the question here is not about the dosis, is about understanding if the Metro inside those solutions is sensitive to daylight or not… I guess that given the fact this is a medicin used for intravenal usage in humans, it should be shipped in light-proof container if there’s any risk of Metro being spoiled by daylight, not in a clear glass container!


Regards

[bluelagoon]

Your answer is yes. Keep the injectable in a stable temperature of 20-25c away from moisture and light. The solution will have a few sodium added ingredients to help keep stable and dissolved.

PS..Most injectable bottles come in clear bottles for easy viewing by health care providers but are kept in the fridge or cupboards.

[brewmaster15]

Your answer is yes. Keep the injectable in a stable temperature of 20-25c away from moisture and light. The solution will have a few sodium added ingredients to help keep stable and dissolved.

PS..Most injectable bottles come in clear bottles for easy viewing by health care providers but are kept in the fridge or cupboards.

Exactly.


... and Carlos the bottle is clear because the Dr is supposed to discard it if cloudy..so you need to be able to see it.

al

[bluelagoon]

Also, do not sun bathe while on it or many other antibiotics. That's why lights should be out during fish treatments. A Dr. or pharmacist would have that written on the label for human consumption.

[carlosf]

Hi Al and Mervin,

I was really confused about Metro being daylight sensitive and the fact it is being stored in clear glass containers, that did not make sense to me. It would not be hard to combine both requirements: 1) protect the solution from daylight and 2) allow a healthcare provider to check the content before using it, for instance a container with a protective wrap foil would be enough, I guess. After all, we are talking about injectable solutions for human usage, I would expect extra attention to protect the medicin.

Anyway, I found this scientific article talking about the Metro sensitiveness to light and UV irradiation:
https://www.nature.com/articles/s41598-022-15625-5

It starts like this:
“Metronidazole in aqueous solution is sensitive to light and UV irradiation…”

Degradation rate:
“…Photodegradation of metronidazole in the vaginal lotion (about 14% degradation under 5000 lx for 30 days) was detected under the conditions mentioned above. A similar photosensitization trend was observed in aqueous solutions of metronidazole drug substance with ~ 12% loss….”

Regarding the extra attention I’ve talked about before, the article author writes this:
“… Unfortunately, the instruction leaflet of marketed metronidazole injections only warned to protect from light during storage while their containers were not light-resistant and no light-protection precautions were proposed during administration…”

So, given the degradation rate observed, if it not properly stored for sure it will loose efficiency.
Conclusion: it’s better to use Metro pills

Hope it’s helpful. Regards

[brewmaster15]

Thank you Carlos for the additional information!
al

[bluelagoon]

It not only degrades under UV. But like I said there have been documented cases where a small minority people react to it when exposed to sun light, like itching, rash and blisters are a few lesser side effects. "Maybe" some fish have the same reactions from the drug too when lights are on; I'm not sure if that is so tho with fish.

[brewmaster15]

It not only degrades under UV. But like I said there have been documented cases where a small minority people react to it when exposed to sun light, like itching, rash and blisters are a few lesser side effects. "Maybe" some fish have the same reactions from the drug too when lights are on; I'm not sure if that is so tho with fish.

I don't know about metro causing these reactions in some fish but I do know Tetracycline can cause discus to get jumpy.. real jumpy. Interestingly people can be photosensitive when on tetracycline/doxycyclines... andb it causes rashes, sun burns etc.