Pergolide versus Pergolide Mesylate Dosing #pergolidestrength


Ian Hudgings
 

Is there a summary of the information the group has gathered on the topic? I'm a little rusty on finding things on the group. But I've done some research of my own and would like to compare notes.

Thanks,
Ian
ThrivingPets
Denver CO
member since 2004 (I think)


Kathy Brinkerhoff
 

Hi Ian,

Here is the post from Dr. Kellon regarding the pergolide mesylate/Prascend "mystery".

Kathy Brinkerhoff

SE/WI  10/12

Dr. Kellon posts on CIR 0615 (Cushing's Insulin Resistance Course):

This is the reply from BI:

Thank you for contacting Boehringer Ingelheim Veterinary Technical Services. You raised a very good question that, frankly, took a few days to circulate and find the answer.

 

The brief answer is, Prascend is the same worldwide. So, as you identified, the language is different from US & UK. No matter US or UK, there is 1.3 mg of pergolide mesylate (the salt) and once metabolized, 1 mg of pergolide.

 

So, to answer your question below, 1 tablet contains 1 mg of actual pergolide (1.3 mg of pergolide mesylate).

 

Let us know if you have further questions.

 

Best regards,

 

Kerby Weaver, DVM

Technical Service Veterinarian

A Boehringer Ingelheim Vetmedica Inc.





 

Ian, If you search for "pergolide mesylate" in the search box on the website for Conversations, you will pull up these threads from late summer and fall 2015.  See, for example, the preceding messages with the same subject title Kathy mentioned. The beginning of the discussion started with questions about this issue at Pet Health Pharmacy and confusion about whether a prescription for 1 mg "pergolide" is equivalent to 1 Prascend. 

An earlier discussion: 
I believe that 9 Prascend does appear to contain more active drug than 9 mg compounded pergolide. This weekend I substituted Prascend when I temporarily ran out of compounded capsules. While my 23 yo horse does not ordinarily suffer the pergolide "veil," she did get immediate diarrhea from 9 Prascend which she did not have from 9 mg of compounded pergolide. She also showed signs of less insulin resistance, with clear, non-runny eyes. 

Cass for Satra
Sonoma County, Calif. Oct. '12


Lisa S
 

Kathi,

Since the topic came up again, I would like to quote from another of Dr. Kellon's posts on the pergolide versus pergolide mesylate thread from September. This post helped clarify for me exactly what the prescriber needs to write to make sure that there is no misunderstanding of terms. Glad to see this topic again, I had forgotten to save this answer!

From September 25, 2015:
So, for clarity's sake, when a veterinarian is writing a script for pergolide, and he wants to insure that the amount given will be, shall we say for example, .5 mg, what is the best way for that script to be worded?

= = = = = = = = 

0.5 mg of actual pergolide from pergolide mesylate - i.e, 0.655 mg of pergolide mesylate.

Eleanor in PA
www.drkellon.com

 



Ian Hudgings
 

I do not know, and will not comment on what Boehringer and Pet Health are doing, but felt it would be helpful to make a couple of points. Plumb's Veterinary Drug Handbook, Fifth Edition lists Pergolide Mesylate and provide dosing for Pergolide Mesylate. PCCA (Professional Compounding Centers of America) provides a formula for compounded Pergolide Mesylate Suspension. PCCA's 30ml suspension of Pergolide Mesylate 1 mg/ml contains 30 mg of Pergolide Mesylate. If the Veterinary Drug Handbook and premier resource for compounding medications list dosing and compounding directions for Pergolide Mesylate, I'm included to think that most veterinarians and pharmacies dose this medication in mg of Pergolide Mesylate.

I would be happy to send copies of the PCCA formula and Plumb's Pergolide Mesylate if the group would like them for the files.

-Ian
www.thrivingpets.com


Eleanor Kellon, VMD
 

Prascend and Pet Health, like Permax before them, are producing pergolide tablets/capsules according to the USP definition of a pergolide tablet which is 90 to 110% of the labelled amount of pergolide - NOT the amount of pergolide mesylate (or sulfoxide)

   Pergolide Tablets, chemical structure, molecular formula, Reference Standards

 

This means that pergolide capsules from Thriving Pets contain less actual pergolide than a 1 mg Prascend. It takes about four 1 mg Thriving Pet pergolide capsules to equal three 1 mg Prascend.

That is the information our members need if contemplating a change in drug supplier.

Pergolide = C19H26N2S

Pergolide mesylate = C19H26N2S . CH4O3S

To be consistent with USP, products based on weight of pergolide mesylate, not weight of pergolide, should be labeled as pergolide mesylate while those based on weight of pergolide should be called simply pergolide.


Eleanor in Pa
www.drkellon.com
EC Co-owner
Feb2001


 

This has been a very interesting discussion for me because I use a combination of both products.  I had no idea until recently that the preparations were formulated differently.  No wonder 1 mg of compounded pergolide is promoted as less effective than 1 mg of Prascend.

To be consistent with USP, products based on weight of pergolide mesylate, not weight of pergolide, should be labeled as pergolide mesylate while those based on weight of pergolide should be called simply pergolide. 


Eleanor in Pa 
www.drkellon.com 
EC Co-owner 
Feb2001 

if one looks at the pink box that Prascend comes in, four of the six sides are labeled with the contents.  Three of those four describe the contents as 1 mg of pergolide mesylate and one side describes it as 1 mg pergolide as pergolide mesylate.  If that isn’t confusing (to me), I don’t know what is.


Martha in Vermont
June 2012


Lorna Cane
 




>>  No wonder 1 mg of compounded pergolide is promoted as less effective than 1 mg of Prascend.



   But Prascend is described as pergolide mesylate on the label insert, 1 mg :


Eleanor Kellon, VMD
 

   But Prascend is described as pergolide mesylate on the label insert, 1 mg :
= = = = = = =

That is confusing, but if you go here under Description it says "pergolide, as pergolide mesylate"

DailyMed - PRASCEND- pergolide mesylate tablet

 

and this, for the European product which is the same, is even more clear:

http://www.viovet.co.uk/Prascend_for_Horses/c3216/

 


Lorna Cane
 




>>and this, for the European product which is the same, is even more clear:

http://www.viovet.co.uk/Prascend_for_Horses/c3216/



For me, this ( from your link above) is the only one which makes sense:

"Each tablet contains 1.0 mg pergolide (as pergolide mesylate 1.31 mg)."

The addition of *pergolide mesylate 1.31 mg* makes all the difference. Sigh.





 


Kathy Brinkerhoff
 

Hi All,

I posted this email from Boehringer Ingelheim to Dr. Kellon a couple of weeks ago.   Lj  started this discussion a couple of months ago because when he read his prescription label from Pet Health Pharmacy it stated that the capsules in the bottle contained 4 mg of pergolide mesylate and he wanted to know why it stated 4 mg since Jesse needed 3 mg of pergolide daily.  I followed up because I needed to transition my horse from 3 mg of Prascend to 3 mg of compounded pergolide.  I called BI and was told by a vet tech that 1 mg of prascend is equal to 1 mg of pergolide mesylate which based on the email below was incorrect information.  Other members posted Prascend inserts  from the UK and France that stated that 1 mg of Prascend is formulated from 1.3 mg of pergolide mesylate.  So why the difference in the US insert information for a product that is supposed to be the same "world wide" ??   I posted the question on CIR0615 because this was very confusing to me and Dr. Kellon contacted BI posted her email response from BI.   In the email response Dr. Weaver states the "language is different from US to UK"  ??? What does that mean?  Simply put worldwide 1 mg of Prascend is "metabolized" from 1.3 mg of pergolide mesylate.  So if my horse is on 3 mg of Prascend and I switch to a compounding pharmacy and I want the dosage the same I need 3.9 mg/4mg of pergolide mesylate to fulfill my prescription request of 3 mg of pergolide.  One needs to know how your compounding pharmacy is formulating/metabolizing the prescription your vet sends to them.  

This is my understanding of the Prascend vs Pergolide Mesylate dosing discussion.

Kathy



Dr. Kellon's Post (CIR 0615)

This is the reply from BI:

Thank you for contacting Boehringer Ingelheim Veterinary Technical Services. You raised a very good question that, frankly, took a few days to circulate and find the answer.

 

The brief answer is, Prascend is the same worldwide. So, as you identified, the language is different from US & UK. No matter US or UK, there is 1.3 mg of pergolide mesylate (the salt) and once metabolized, 1 mg of pergolide.

 

So, to answer your question below, 1 tablet contains 1 mg of actual pergolide (1.3 mg of pergolide mesylate).

 

Let us know if you have further questions.

 

Best regards,

 

Kerby Weaver, DVM

Technical Service Veterinarian

A Boehringer Ingelheim Vetmedica Inc.




  





Kathy Brinkerhoff
 

Hi All,

Post got away from me and my signature and I now read/see that Dr. Kellon already "cleared up" the discussion.

Kathy Brinkerhoff

SE/WI  10/12






 

I know no one needs more work right at this moment....but would it be possible to include this critical information in the Pergolide 101 document (or a better location)? This distinction is easy to miss.

Cass for Satra
---In EquineCushings@..., <drkellon@...> wrote :

Prascend and Pet Health, like Permax before them, are producing pergolide tablets/capsules according to the USP definition of a pergolide tablet which is 90 to 110% of the labelled amount of pergolide - NOT the amount of pergolide mesylate (or sulfoxide)

   Pergolide Tablets, chemical structure, molecular formula, Reference Standards

 

This means that pergolide capsules from Thriving Pets contain less actual pergolide than a 1 mg Prascend. It takes about four 1 mg Thriving Pet pergolide capsules to equal three 1 mg Prascend.

That is the information our members need if contemplating a change in drug supplier.

Pergolide = C19H26N2S

Pergolide mesylate = C19H26N2S . CH4O3S

To be consistent with USP, products based on weight of pergolide mesylate, not weight of pergolide, should be labeled as pergolide mesylate while those based on weight of pergolide should be called simply pergolide.


Eleanor in Pa
www.drkellon.com
EC Co-owner
Feb2001


Ian Hudgings
 

I just got off the phone with Rich Gaffin, R.Ph. of Pet Health Pharmacy. Pet Health supplies compounded Pergolide Mesylate. As previously mentioned, compounding formulas are supplied for Pergolide Mesylate (not Pergolide USP or base). Rich guaranteed me that they dispense Pergolide Mesylate and that they do NOT dispense based on Pergolide base. He mentioned that since Prascend has come along they counsel their clients about the 1.305 Pergolide Mesylate to Pergolide base conversion to try to keep the same dose but they do not compound in Pergolide base doses. The net result is, that ThrivingPets and Pet Health (and most likely the majority of other compounding pharmacie as well) compound Pergolide Mesylate. BI makes Prascend in 1mg Pergolide base tablets (1.305mg of Pergolide Mesylate).

I have reached out to Donald Plumb of Plumb's Veterinary Drug Handbook to see if the dosing his publication provides for Pergolide Mesylate is for Pergolide base of Pergolide Mesylate and will get back to the group when I hear back.

-Ian
ThrivingPets


Nancy C
 

Hi Ian


To your most recent post, It really doesn't matter why you, or anyone else, is producing capsules that contain less than the stated mg of pergolide when compared to Prascend. My concern as a horseowner is if one pharmacy is giving 1 mg of pergolide mesylate vs another who is giving 1.3 mg of pergolide mesylate, I'd want to know so that I may compare cost/benefit.

As pointed out, 3 mg caps of pergolide mesylate would have only 2 mg of pergolide.

If my horse is on a low level of pergolide that has him or her happy and controlled, I might not find this a reason to worry, as suggested by Dr Kellon earlier.  However, at 14 mg per day, it becomes an issue I'd want to look at closely.

It would seem from this discussion that pharmacies may be  compounding at different levels.  If so then dosing levels from Prascend to compound could be different if dosing at the 1 mg of pergolide mesylate per cap.  I would find this a huge bit of helpful info when dealing with vets as well as in understanding my actual costs.

Nancy C in NH
ECIR Moderator 2003
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Thanks, Ian. I, for one, care very much why compounding pharmacies do what they do. Consistency of the compounded drug is central to my willingness to substitute a compounded drug for an FDA approved formulation. 

Cass for Satra
Sonoma County, Calif. Oct. '12

---In EquineCushings@..., <ian@...> wrote :

I just got off the phone with Rich Gaffin, R.Ph. of Pet Health Pharmacy. Pet Health supplies compounded Pergolide Mesylate. As previously mentioned, compounding formulas are supplied for Pergolide Mesylate (not Pergolide USP or base). Rich guaranteed me that they dispense Pergolide Mesylate and that they do NOT dispense based on Pergolide base. He mentioned that since Prascend has come along they counsel their clients about the 1.305 Pergolide Mesylate to Pergolide base conversion to try to keep the same dose but they do not compound in Pergolide base doses. The net result is, that ThrivingPets and Pet Health (and most likely the majority of other compounding pharmacie as well) compound Pergolide Mesylate. BI makes Prascend in 1mg Pergolide base tablets (1.305mg of Pergolide Mesylate).

I have reached out to Donald Plumb of Plumb's Veterinary Drug Handbook to see if the dosing his publication provides for Pergolide Mesylate is for Pergolide base of Pergolide Mesylate and will get back to the group when I hear back.

-Ian
ThrivingPets


Nancy C
 

Hi Cass

I may be splitting haris, but I am interested in what compounders are doing so I may compare.  What is in the final product I am receiving. I hope to learn what questions to ask to determine this.  We have heard from others that compounders are using higher levels of pergoide mesylate. It would be important to not lose that info in the discussion of why one compounder may have a business reason to perform in one way or another.

Again, just my opinion based on the needs of my horse.

Nancy C in NH



---In EquineCushings@..., <cbernstein@...> wrote :

Thanks, Ian. I, for one, care very much why compounding pharmacies do what they do. Consistency of the compounded drug is central to my willingness to substitute a compounded drug for an FDA approved formulation. 

Cass for Satra
Sonoma County, Calif. Oct. '12



Sharon Manning
 

Well this discussion has been over my ability from the very beginning but I have been following it trying to understand. I do understand the simple math in relation to my pocket book. As Nancy points out... I have one horse on 21mg and another on 10mg! Not sure how long I can continue this , so if one Pharmancy gives more bang for the buck I sure would like to know!
Sharon
E TN
2005

Sent from my iPhone
Please forgive any errors


Lorna Cane
 



>> I have one horse on 21mg and another on 10mg! Not sure how long I can continue this , so if one Pharmancy gives more bang for the buck I sure would like to know!


What does the label say?

Does the label say 21mg pergolide from pergolide mesylate?

Or 21mg pergolide mesylate?





Nancy C
 

Hi Sharon

Without getting too far into the weeds, that is what we are trying to sort out.

Nancy C in NH
Feburary 2003
ECIR Group Mod