I have a question about dosing Cipro

[Randy Holmes-Farley Verified Community Expert]

https://pubmed.ncbi.nlm.nih.gov/2081719/​

Solutions of ciprofloxacin were irradiated with different wavebands of ultraviolet and visible radiation and the antibiotic activity of the drug was determined against Escherichia coli. A wavelength dependent loss of antibiotic activity was found with maximal effect around 320 nm; no effect occurred with visible irradiation. The degree of the decrease in activity with longer wavelength ultraviolet (UVA) radiation was sufficient to indicate that human exposure to sunlight through window glass (greater than 320 nm) or UVA from tanning sunbeds may result in a significant reduction in both cutaneous and circulating levels of ciprofloxacin.

 

[reefmaster70]

"Ciprofloxacin is highly photosensitive and breaks down under ultraviolet (UV) and near-UV radiation. While its absolute peak absorption occurs in the deep UV spectrum (around 270–280 nm), it remains highly photolabile under UVA and near-visible violet wavelengths (320–420 nm). Modern reef aquarium LED fixtures intentionally output a heavy concentration of these exact violet (410–420 nm) and near-UV (380–400 nm) wavelengths to stimulate coral fluorescence." (Royal Society of Chemistry)

 

[Randy Holmes-Farley Verified Community Expert]

"Ciprofloxacin is highly photosensitive and breaks down under ultraviolet (UV) and near-UV radiation. While its absolute peak absorption occurs in the deep UV spectrum (around 270–280 nm), it remains highly photolabile under UVA and near-visible violet wavelengths (320–420 nm). Modern reef aquarium LED fixtures intentionally output a heavy concentration of these exact violet (410–420 nm) and near-UV (380–400 nm) wavelengths to stimulate coral fluorescence." (Royal Society of Chemistry)

Link?

I show the paper with the actual data. There is very little degradation at reef tank wavelengths.

 

[JGT]

Interesting… The link to the study provided by @RSNJReef does indicate that while not as drastic as UV lighting, what they call “indoor fluorescent lighting” does degrade Cipro.

 

[Randy Holmes-Farley Verified Community Expert]

Interesting… The link to the study provided by @RSNJReef does indicate that while not as drastic as UV lighting, what they call “indoor fluorescent lighting” does degrade Cipro.

The paper I posted shows zero degradation when irradiated at 400 or 430 nm, but is degraded by 365 nm and shorter wavelengths.

 

[RSNJReef]

So, have been looking some of this up, and, there are a number of factors that would degrade cipro in an aquarium, like light, ph of the water, dissolved organics, and the bacterial load, all which would act as catalysts.

For example, ph effects under broad spectrum light shown below:
https://pmc.ncbi.nlm.nih.gov/articles/PMC8196772/

Unfortunately I have not found a study specific to our reef tank conditions, but I’d envision we can all agree that it does degrade somewhat. Would it stay at 100% over 24 hours, probably not. Would it go to 0 after 7 days, definitely not.

Unfortunately until someone does a study using a 2+ year old established reef tank and sends out daily samples to a lab for composition analysis of cipro, we won’t be able to say exactly how fast it degrades.

I think we can agree though at this stage that a single dose at 50-100x the recommended dosage may not end well, and neither would under dosing 4 times a day.

The one thing I do see through these posts though is there are a lot of ways to successfully do this, as long as you stay within the general guard rails.

 

[Randy Holmes-Farley Verified Community Expert]

So, have been looking some of this up, and, there are a number of factors that would degrade cipro in an aquarium, like light, ph of the water, dissolved organics, and the bacterial load, all which would act as catalysts.

For example, ph effects under broad spectrum light shown below:
https://pmc.ncbi.nlm.nih.gov/articles/PMC8196772/

Nothing in that paper suggests it would degrade by light in a reef tank.

It is far more likely, IMO, for it to bind to things like calcium carbonate (it does in fresh water, but likely less so from seawater) or organic detritus (it is known to bind to surfactants) than to photodegrade. But a study showing any decline in Cipro day to day in a reef tank would be needed, IMO, to suggest a dosing scheme where it is redosed every 24 h.

 

[JGT]

The paper I posted shows zero degradation when irradiated at 400 or 430 nm, but is degraded by 365 nm and shorter wavelengths.

Interesting, would be good to see the paper that @reefmaster70 posted an extract from as that seems to have contradictory findings. And then who do we believe ?
The link to the paper RSNJReef provided didn’t provide the nm for the fluorescent lighting. Did a search and it seems to be in the upper range (400-700nm) but pretty variable based upon type of fluorescent lighting (cool, warm, white, etc.)

 

[JGT]

So, have been looking some of this up, and, there are a number of factors that would degrade cipro in an aquarium, like light, ph of the water, dissolved organics, and the bacterial load, all which would act as catalysts.

For example, ph effects under broad spectrum light shown below:
https://pmc.ncbi.nlm.nih.gov/articles/PMC8196772/

Unfortunately I have not found a study specific to our reef tank conditions, but I’d envision we can all agree that it does degrade somewhat. Would it stay at 100% over 24 hours, probably not. Would it go to 0 after 7 days, definitely not.

Unfortunately until someone does a study using a 2+ year old established reef tank and sends out daily samples to a lab for composition analysis of cipro, we won’t be able to say exactly how fast it degrades.

I think we can agree though at this stage that a single dose at 50-100x the recommended dosage may not end well, and neither would under dosing 4 times a day.

The one thing I do see through these posts though is there are a lot of ways to successfully do this, as long as you stay within the general guard rails.

Amen brother, amen!

 

[StartingATank]

So, have been looking some of this up, and, there are a number of factors that would degrade cipro in an aquarium, like light, ph of the water, dissolved organics, and the bacterial load, all which would act as catalysts.

For example, ph effects under broad spectrum light shown below:
https://pmc.ncbi.nlm.nih.gov/articles/PMC8196772/

Nothing in that paper suggests it would degrade by light in a reef tank.

It is far more likely, IMO, for it to bind to things like calcium carbonate (it does in fresh water, but likely less so from seawater) or organic detritus (it is known to bind to surfactants) than to photodegrade. But a study showing any decline in Cipro day to day in a reef tank would be needed, IMO, to suggest a dosing scheme where it is redosed every 24 h.

I do have a good amount of detritus, is there a way for me to know if it is organic or not?

 

[RSNJReef]

I do have a good amount of detritus, is there a way for me to know if it is organic or not?

Don’t chase the DOC dragon yet, it’ll eat you alive.

Just stick to the basics and follow what the guys on here are telling you, dose at the volumes mentioned for 7-10 days and you should be ok.

 

[Randy Holmes-Farley Verified Community Expert]

Interesting, would be good to see the paper that @reefmaster70 posted an extract from as that seems to have contradictory findings. And then who do we believe ?
The link to the paper RSNJReef provided didn’t provide the nm for the fluorescent lighting. Did a search and it seems to be in the upper range (400-700nm) but pretty variable based upon type of fluorescent lighting (cool, warm, white, etc.)

True, I do not know what the important differences may be. I’ll have to read them more carefully later, including with an eye to what (if anything) the more recent one says about the earlier one.