Beneficial effects of furosemide

[sighthound]

http://www.bloodhorse.com/horse-racing/articles/51433/study-shows-furosemide-has-beneficial-effects

[smalltimer]

TGJB,
How long do we have to participate in your forums before we are bestowed our honorary Pharmaceutical Degrees?

[TGJB]

Participating is not enough. You have to understand the significance.

[smalltimer]

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?

[sighthound]

“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.”

[BB]

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.

[TGJB]

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?

[sighthound]

>>> 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)

[sighthound]

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.

[TGJB]

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?

[sighthound]

>> 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.

[TGJB]

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.

[sighthound]

>> 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.

[smalltimer]

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.

[sighthound]

??  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?