Pentosan - how often do you give it?

[stb]

At the recommendation of a new vet, I have started my gelding on Pentosan injections. My guy has a little bit of hock arthritis and a little bit of arthritic changes in the right fetlock due to an old injury (ex roping horse). Clinically he looks good, but I just want to keep him sound and feeling good for as long as possible. The new vet suggested weekly Pentosan injections. Seems a bit much to me, as most people that I know of are giving it every two weeks, and most of those horses have clinical findings.

I don’t want to be second guessing my vet, but just wondered what the norm was as far as Pentosan dosing.

My horse is in light work - mostly trail rides at an easy pace about 3 times a week.

[UrbanHennery]

I did the 4 week loading dose and give it every 4 weeks on the recommendation of my vet. When my horse is working extra hard (shows, heavy training), I give it more often, or will do 2 weeks in a row.

[jawa]

My vet had me give a dose every 4 days for 7 doses and then monthly after that.

I have heard of people giving it once a week for 4 weeks and then monthly after that.

I have also heard of people doing the loading dose and then needing to use it every 2-3 weeks.

[beau159]

I’ve got my horse on Adequan instead of Pentosan, but they have similar uses.

There is a little discrepancy between vets and who you talk to because there really isn’t anything in the literature to support it one way or the other. Some vets say to give the loading dose a few times a year. Others say to the do the loading dose and then once a month. And then you’ll find everything in-between. There just isn’t the research to back it up.

With that said, I would do the loading dose on your horse (once every 4 days for 7 doses) and then start doing once a month. Pay attention to how your horse feels after the loading dose, and how they feel when you drop it down to once a month. Then adjust accordingly. Trial and error.

[Laurierace]

The loading dose for pentosan is not the same as adequan. It is once per week for four weeks then once per month. My guy is a couple weeks shy of 27 so he gets it once per week every week.

[stb]

I should clarify, my vet wants me to give shots weekly from now on out. The weekly shots are not just for loading. I would be more comfortable with the 4 week loading, then monthly or twice monthly after that.

[Laurierace]

I think that is overkill for most horses and is not the norm.

[stb]

Laurierace, did you work up to weekly shots? I can see weekly shots with an older horse, but my guy is only 14. Weekly shots seem a bit much at this point.

[Laurierace]

Yes, he was on the loading dose and then the monthly for years. Then we went down to three weeks then two and now once per week although I don’t follow that schedule exactly. He might go two weeks now and then. For what it’s worth, he used to have to have his hocks injected twice per year and hasn’t had them done once since starting pentosan. Some of that may be due to fusing but it really dose help him quite a bit. We try to ride him at least three times per week just to keep him supple and strong through his back.

[stb]

Thanks everyone. I think I will put him on monthly after the loading dose.

[Danier]

Weekly seems excessive, I don know that it would be harmful, but it may not be necessary (and extra $$ for you)
My horse was unrideable before the pentosan, I did once a weeks for four weeks, then monthly after that. Now I give it as necessary, sometimes every four weeks, sometimes three weeks. I can tell when she needs it.
If I were you I would do the loading dose then see how often your horse needs it.

[gumshoe]

Once a week for 4 weeks then once every 3 weeks. I just didn’t want to take the chance at once every 4 weeks not working. I could be wasting money but I want it to work.

[wendy]

Actually, all of the limited evidence suggests that doing it once a month or once a week is a waste of money. The dose is every four days for seven doses and then nothing for six months or until the horse starts to show symptoms again at which point you are supposed to re-do the “loading” dose. Like most drugs, it has to reach a certain concentration before it works, and the loading dose is what allows that to happen. Often you won’t see any really obvious effect until a good eight weeks after starting the dosing procedure, aka about a month after you finish the loading dose. Which is where I think the once a month procedure came from- someone finished the loading dose, didn’t see much effect, gave one more dose a month later and voila, a sudden effect. Any sudden effect you think you see after giving one shot of the stuff is very unlikely to be related to the one shot, considering the mechanism of action.

[katyb]

[QUOTE=wendy;7910296]
Actually, all of the limited evidence suggests that doing it once a month or once a week is a waste of money. The dose is every four days for seven doses and then nothing for six months or until the horse starts to show symptoms again at which point you are supposed to re-do the “loading” dose. Like most drugs, it has to reach a certain concentration before it works, and the loading dose is what allows that to happen. Often you won’t see any really obvious effect until a good eight weeks after starting the dosing procedure, aka about a month after you finish the loading dose. Which is where I think the once a month procedure came from- someone finished the loading dose, didn’t see much effect, gave one more dose a month later and voila, a sudden effect. Any sudden effect you think you see after giving one shot of the stuff is very unlikely to be related to the one shot, considering the mechanism of action.[/QUOTE]

I don’t think that is the dosage for Pentosan.

[Laurierace]

[QUOTE=katyb;7910305]
I don’t think that is the dosage for Pentosan.[/QUOTE]
It isn’t. That is adequan.

[TWH_Girl]

Well, I had been doing every two weeks, but in the last 45 days or so, my guy seems to have deteriorated a bit. He’s got OCD of the R stifle, and it’s caused some swelling, and reluctance to do much. So, I talked to my vet and we are doing weekly until spring, at which time I plan to have his stifles and SI injected again as I did last year. He went great for about 9 months on the every 2 weeks. Stifle ocd is a bit different than hock arthritis though, and after the loading dose, I think it depends on the symptoms the horse is exhibiting and his workload.

[Char0308]

I did loading dose and then went to every two weeks. One of my vets for her own horses does Pentosan once every two weeks and adequan every two weeks when horse doesn’t get Pentosan; both after initial loading doses. I know some people who do Pentosan once a month or every 3 weeks, just depends on the horse.

[kerlin]

I think once a month after the loading dose is a good place to start. We did that for about 9 months, and then moved up to once every three weeks, with great results. He was just feeling NQR in that fourth week, and every three weeks is a good sweet spot. He’s 20, with no real history of specific problems, in moderate work.

In short, it really depends on the horse. I wouldn’t have a problem with going once weekly if he needs it, but I don’t think it would make a significant difference. For a horse just starting out, at such a young age & in such good overall condition, I think once every 4 weeks is probably a good first step.

[xcatheart]

Or you can follow what Pentosan suggests (which is similar to Adequan except it is every 5-7 days (instead of Adequan’s every 4) for 4 doses (vs Adequan’s 7):

DOSEAGE & ADMINISTRATION - Administer at a dose rate of 3 mg/kg bodyweight (1.5 g / 500 kg horse), by intramuscular injection, at 5 - 7 day intervals for four injections. PENTOSAN EQUINE is equally effective when given by intramuscular or intra-articular injections. If intra-articular use is required, administer 1mL by sterile intra-articular injection. PPS has an affinity for cartilage, and active drug levels will accumulate for several days after administration. For maximum effect, tissues should be exposed to the drug over an extended period, hence the four injections. A period of improvement for up to 6 months following a course of four injections may be expected. If at any time during this period the horse becomes sore (e.g. following a particular activity), it is safe to administer a further injection to settle any inflammatory process.

[stb]

Thanks, everyone, for letting me know how you use the drug. And thanks to xcatheart for the manufacturer’s dosage directions.