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General Category => Ask the Experts => Topic started by: sighthound on June 29, 2009, 04:05:03 PM

Title: Beneficial effects of furosemide
Post by: sighthound on June 29, 2009, 04:05:03 PM
http://www.bloodhorse.com/horse-racing/articles/51433/study-shows-furosemide-has-beneficial-effects
Title: Re: Beneficial effects of furosemide
Post by: smalltimer on June 29, 2009, 04:10:00 PM
TGJB,
How long do we have to participate in your forums before we are bestowed our honorary Pharmaceutical Degrees?
Title: Re: Beneficial effects of furosemide
Post by: TGJB on June 29, 2009, 04:16:53 PM
Participating is not enough. You have to understand the significance.
Title: Re: Beneficial effects of furosemide
Post by: smalltimer on June 29, 2009, 05:22:44 PM
I\'m a product of the \'60\'s, so I know a thing or two about the effects of drugs.
I have friends who want to \"save the world\", but all they ever do is smoke pot and play frizbee.
So....significance aside, does usage count?
Title: Re: Beneficial effects of furosemide
Post by: sighthound on June 29, 2009, 05:46:08 PM
"The challenge will now be for countries such as England, Hong Kong, Australia and South Africa that do not currently permit race-day use of furosemide.   The challenge that they will face is balancing the animal-welfare aspect of being able to prevent or reduce the condition against the imperatives for drug-free racing.   Additionally, instituting race-day administration of furosemide would be a significant added expense to racing."
Title: Re: Beneficial effects of furosemide
Post by: BB on June 30, 2009, 03:03:55 AM
Sight, does this study show that furosemide is beneficial to ALL horses? In other words, if all horses got race day treatment would they all benefit, health-wise? Or, would horses with minimal bleeding get an immaterial benefit?

Either way, I\'d think, the dilemma posed for the Euros and others is really something. It will be interesting to see the international reaction to this study.
Title: Re: Beneficial effects of furosemide
Post by: TGJB on June 30, 2009, 09:45:47 AM
There may be other issues involving dosage, too. I\'ve heard this is not regulated-- Sight? Is there a minimal amount that a) works, b) stops bleeding but doesn\'t cause 18 pounds of weight loss, and c) can be regulated?
Title: Re: Beneficial effects of furosemide
Post by: sighthound on June 30, 2009, 01:05:44 PM
>>> Sight, does this study show that furosemide is beneficial to ALL horses?

The easy answer is \"yeah\", the technical answer is that all horses in the world cannot be measured .  

The study showed a clear and definitive benefit to the horses involved in the study, at a statistically significant (and reliable) incidence.  The authors saw no reason for the results in the horses studied not to be extrapolatable to TB\'s in other jurisdictions.

>> In other words, if all horses got race day treatment would they all benefit, health-wise?

Yes

>> Or, would horses with minimal bleeding get an immaterial benefit?

No.  They would also benefit.

The study states this: \"Results of the present study provide strong evidence that furosemide can help prevent the development of EIPH in Thoroughbred racehorses.\"

>> Either way, I\'d think, the dilemma posed for the Euros and others is really something. It will be interesting to see the international reaction to this study.

Yes!  

We will also have to see if the scientific world has any comment.  I\'ve only read the study through once, but nothing jumps out at me.  It was very well-done, on a technical basis (goes to accuracy, reliability, that type of thing)
Title: Re: Beneficial effects of furosemide
Post by: sighthound on June 30, 2009, 01:41:35 PM
I would recommend folks click on the Bloodhorse page study link, click on the study itself (7 pages) and read the \"Experimental protocol\", under \"Materials and Methods\" -  how they recruited real racehorses to do this (down to the same jockeys, tack, starting gate hole, etc) - how it was \"blinded\" so even the placebo administered physically looked like lasix - very interesting.


>> There may be other issues involving dosage, too.

The dose used in this study was the standard and widely used dose for horse racing, 500mg.

BTW, lasix dose can easily and readily affect TCO2 concentrations.

>> I\'ve heard this is not regulated-- Sight? Is there a minimal amount that
>> a) works

Lasix use is extremely tightly regulated (amount, time frame when it can be administered)  The usual dose is 250 to 500mg per horse, nearly always 500mg.

>> b) stops bleeding but doesn\'t cause 18 pounds of weight loss,

No.  That\'s what lasix does - it\'s a diuretic.  18 pound loss of body water in a 1000-1200 pound horse.

>>> and c) can be regulated?

Lasix can be detected to quite minute trace levels.

Here are the RMTC Model Rules regarding lasix use, from:   http://www.rmtcnet.com/resources/Chapter_11_Model_Rules_1-09.PDF


The use of furosemide shall be permitted under the following circumstances on association grounds where a detention barn is not utilized:

(a) Furosemide shall be administered no less than four hours prior to post time for the race for which the horse is entered.

(b) The furosemide dosage administered shall not exceed 500 mg. nor be less than 150 mg.

(c) Furosemide shall be administered by a single, intravenous injection.
 
(d) The trainer of the treated horse shall cause to be delivered to the official veterinarian no later than one hour prior to post time for the race for which the horse is entered the following information under oath on a form provided by the Commission:

(A) The name of the horse, racetrack name, the date and time the furosemide was administered to the entered horse;

(B) The dosage amount of furosemide administered to the entered horse; and

(C) The printed name and signature of the attending licensed veterinarian who administered the furosemide.

(4) Test results must show a detectable concentration of the drug in the post-race serum, plasma or urine sample.

(a) The specific gravity of post-race urine samples may be measured to ensure that samples are sufficiently concentrated for proper chemical analysis. The specific gravity shall not be below 1.010. If the specific gravity of the urine is found to be below 1.010 or if a urine sample is unavailable for testing, quantitation of furosemide in serum or plasma shall be performed;

(b) Quantitation of furosemide in serum or plasma shall be performed when the specific gravity of the corresponding urine sample is not measured or if measured below 1.010. Concentrations may not exceed 100 nanograms of furosemide per milliliter of serum or plasma

---------------
I\'d like to note that veterinarians have been fined for administering lasix even 5 minutes outside of the time allocated, for failure to deliver the signed form, etc.
Title: Re: Beneficial effects of furosemide
Post by: TGJB on June 30, 2009, 01:48:36 PM
If I read that correctly (debatable), they can give anywhere from 150 to 500 at their own discretion. Are there quantitative tests? Do they do them? Are they allowed to give 150 this time, then 500, then back to 150? Would anyone (let alone the public) know?
Title: Re: Beneficial effects of furosemide
Post by: sighthound on June 30, 2009, 01:57:40 PM
>> If I read that correctly (debatable), they can give anywhere from 150 to 500 at their own discretion.

Those are the model rules.  Individual states may vary.  Nearly all horses receive 500mg.  Some may receive 250mg, but that\'s rare.  If you want to prevent bleeding, you do it.

>> Are there quantitative tests?  Do they do them?

The model rules give examples, but ask the individual racing jurisdiction what they do, exactly.

>> Are they allowed to give 150 this time, then 500, then back to 150?

They could with approval, but why in the world would anybody want do that?  It would be stupid.  You don\'t want the horse to bleed:  they stop, they can have permanent scarring, it takes longer to get back to the next race ...

>>  Would anyone (let alone the public) know?

Yes, the actual dose given is on the form every vet fills out for every lasix-receiving horse in every current jurisdiction.

If you want lasix dose published (rather than just the \"L\" as it is now) petition the racing jurisdictions.  I couldn\'t see any point to it.
Title: Re: Beneficial effects of furosemide
Post by: TGJB on June 30, 2009, 02:08:39 PM
You are assuming that all horses getting Lasix are actually bleeders, which as you know is not true. If the weight they shed is a function of how much they are given, all kinds of games can be played.

And even with real bleeders, the public often does not know when they bleed through lasix. A bad performance followed by a dosage switch from 150 to 500 would be information I would like to have.
Title: Re: Beneficial effects of furosemide
Post by: sighthound on June 30, 2009, 02:15:17 PM
>> You are assuming that all horses getting Lasix are actually bleeders, which as you know is not true.

??? What are you talking about?  The doses?

>> If the weight they shed is a function of how much they are given, all kinds of games can be played.

Losing 20 pounds of water and electrolytes is a good thing compared to losing 15 pounds of water and electrolytes ... ?  Sorry, Jerry, don\'t go there, there\'s nothing there at all.

Edit:  in other words, the lasix-induced changes in pressure, dehydration, etc. can help prevent or attenuate the EIPH, but losing the electrolytes and water is not what an athlete needs right before a race.  It\'s a trade off.

The weight they shed is not dependably dose dependent, there are several variables.

>> And even with real bleeders, the public often does not know when they bleed through lasix.

Yes, the medical records of horses in the USA are not public.

>> A bad performance followed by a dosage switch from 150 to 500 would be information I would like to have.

Highly doubtful that happens.  And if it did, highly doubtful it would do anything but not work, and more likely for the horse to bleedin during the race.    

As I said, nearly all horses get 500mg.  A horse would only get a little less if they were really wrung out (at the finish, electrolyte-wise) last race.

Bleeding into the lungs is also a function of the physical pounding a racehorse
takes running over the ground.  Horses were not designed by nature to do that.
Title: Re: Beneficial effects of furosemide
Post by: smalltimer on June 30, 2009, 02:18:15 PM
You give them 50mg, run \'em up the track in 7-10 hole and then you administer 500 next trip, or when you\'re going.  That\'s been the game since day 1.  
When they are random testing, probably no more than the top 5 finishers, it sets the really good ones apart.
Title: Re: Beneficial effects of furosemide
Post by: sighthound on June 30, 2009, 02:20:49 PM
??  The above is a crazy silly scenario.  

With all due respect (as you guys aren\'t giving lasix, are not around thousands of horses getting lasix, and seeing how they come out of their races, etc) you guys really don\'t understand how these drugs work.

Edit:  Do you guys realize that most publicized works are on lasix?  But not all?
Title: Re: Beneficial effects of furosemide
Post by: TGJB on June 30, 2009, 02:42:34 PM
Briefly, because in some cases your answers actually made this more confusing--

You know (I have to assume) that virtually all horses race on Lasix, and that only a very small percentage have actually been observed to have bled before having been put on it, even in states where that is supposed to be a pre-requisite.

And it doesn\'t have to be 15 compared to 20 pounds, it could be 5 compared to 15 if you use the lower does first (aside from other variables). And I do know of horses that were given smaller doses, bled through them, then were given a higher one next time, with no intention to cheat. One Graph Racing filly in particular. She shouldn\'t have gotten the lower dose to begin with.

On your last point, I have said that to trainers and owners many times. Bleeding is as likely to be an effect of a problem as a cause.
Title: Re: Beneficial effects of furosemide
Post by: sighthound on June 30, 2009, 02:54:17 PM
>> You know (I have to assume) that virtually all horses race on Lasix, and that only a very small percentage have actually been observed to have bled before having been put on it, even in states where that is supposed to be a pre-requisite.

Yes, but over 85% of horses are thought to be bleeders (much previous work on this in the literature).  Nearly all are not visible on endoscopy post-race.  In other words, horses can bleed a bit, but scope clean post-race.

Read the study - it was done on South African horses that never get lasix to race.

>> And it doesn\'t have to be 15 compared to 20 pounds, it could be 5 compared to 15 if you use the lower does first (aside from other variables).

The body weight of the horse isn\'t exactly like the weight the horse carries on it\'s back.  A pound of body weight is not like a pound of jockey or a pound of lead.

Seriously - the tradeoff in electrolytes lost, and simple body water lost, and the metabolic effects of that, is far more signficant than worrying the horse is racing 15 pounds lighter than normal.  

And the water loss each horse has, for each time it\'s given lasix, is not predictable in the least, as it\'s based upon the horses\' current hydration status, it\'s electrolyte status, when and what it has been eating, and quite markedly by the environmental temperature and humidity.

>> And I do know of horses that were given smaller doses, bled through them, then were given a higher one next time, with no intention to cheat.

Yes, that\'s not rare.  Due to the other side effects mentioned, some trainers want to try a smaller dose.