Cabergoline treatment for acromegaly - side effects

[Bob's Staff]

Hi, we are Bob (12 year old male cat) and his “servant” Kris . We live in Belgium and I ended up here after Bob’s recent diagnosis of acro and me looking for other acro cat parents to hear some experiences.

A bit of context: Bob was already diagnosed earlier with congenital hypothyroidism, hyperaldosteronism, first stage HCM (echo has been repeated recently, nothing changed yet), and very first stage of kidney failure. To which was recently added: acromegaly (IGF-1: 645 ng/ml in January, >1000 ng/ml last month).

Bob doesn’t have diabetes yet (tests are done regularly), but I read a lot of posts here about acro cats being treated with cabergoline. Research about it is not very extensive, but sufficient for our university clinic in Ghent to decide to put our kitty on cabergoline to prevent him from developing diabetes and other discomfort due to his acro.

Our cabergoline was supplied in a bottle of 50 µg/ml, which is sold under the brand name “Galastop” in Belgium. Most research recommends a dose of 10 µg/kg so Bob was prescribed 1,1 ml for his 6,5 kg, to be administered every 24h. He got his first dose last week, only a few hours after which he became totally sleepy. No vomiting or diarrea, and he kept eating very (very!) well, like he’s always done since he has acro. He just had very “squinty” eyes with his third eyelid appearing all the time, like if he was being sedated for surgery. Our vet recommended to temporarily quit the cabergoline and restart with half the recommended dose (so 0,6 ml) every 48h as soon as he would be recovered from his first dose. It took him four days for his sleepiness to disappear and his eyes turn back to normal. Which made me wonder if half a dose will still not be too much, if he already needs 4 days to recover from a whole dose. So today we restarted, with a dose of only 0,4 ml to let his body get used to this stuff.

Anyway, this finally brings me to my question: are there any acro cat parents here who can tell me how long cabergoline side effects like sleepiness/mild sedation and GI problems last? The research says these side effects don’t last more than a week, but I worry too much when our Bob goes into “sedation mode” like that and I don’t feel comfortable giving next doses when he already feels like that, since I cannot see what’s going on inside his body ... Or should I continue anyway if he still becomes so sleepy after this 0,4 ml dose today, and is this a passing thing that will get better after a few days, when his body has gotten used to the cab?

I hope some cat parents here can help me out, since the research doesn’t specify much about side effects and they don’t have any experience with it in Ghent either …

Many thanks for sharing your experiences!

 

[Wendy&Neko]

Hello and welcome. You've definitely got a complicated kitty. I don't think we've had any members with non diabetic cats use cabergoline. The number of non diabetic acros is also very small. I love hearing about these less common cases.

Tagging some recent users of cabergoline who still on here sometimes.
@Suzanne & Darcy @Jodey&Eddie&Blue @Howiesmom

There are other members out there who have used cabergoline, but not posting much if at all. One of our members in Greece also used Galastop. The spreadsheet isn't up to date to see if she's still using it, though her cat was on tiny doses of insulin for the last entries. I also noticed she went from every day to every other dosing after a couple weeks, and kitty was having soft poops the first week, but not reported after that. Not sure I remember the sleepiness/mild sedation effect reported.

This South American group seems have published about the largest research studies on cabergoline:
New paper on: Cabergoline treatment in cats with diabetes mellitus and hypersomatotropism

And for good measure, tagging @SmallestSparrow who also has a kitty with hyperaldosteronism (Conn's), but with Cushings, not acro.

 

[Bob's Staff]

Hello and welcome. You've definitely got a complicated kitty. I don't think we've had any members with non diabetic cats use cabergoline. The number of non diabetic acros is also very small. I love hearing about these less common cases.

Tagging some recent users of cabergoline who still on here sometimes.
@Suzanne & Darcy @Jodey&Eddie&Blue @Howiesmom

There are other members out there who have used cabergoline, but not posting much if at all. One of our members in Greece also used Galastop. The spreadsheet isn't up to date to see if she's still using it, though her cat was on tiny doses of insulin for the last entries. I also noticed she went from every day to every other dosing after a couple weeks, and kitty was having soft poops the first week, but not reported after that. Not sure I remember the sleepiness/mild sedation effect reported.

This South American group seems have published about the largest research studies on cabergoline:
New paper on: Cabergoline treatment in cats with diabetes mellitus and hypersomatotropism

And for good measure, tagging @SmallestSparrow who also has a kitty with hyperaldosteronism (Conn's), but with Cushings, not acro.

Hi, thanks for your welcome message
At first our kitty was a mystery case for our vet, so they turned him inside out to find out what was wrong, after which he became a complicated case with all his diseases
Because Bob is so big, they decided to test his IGF-1 at university clinic. His value only started to raise afterwards, during check-ups to follow up on this value, so they discovered the acro rather accidentally because his size made them suspect he had acro, but he has actually always been that big, even without the acro. I think that's the reason he is acro without diabetes: he hasn't reached that stage yet ...
According to our vet in Ghent, very recent research in the UK with nine cats having acro without diabetes and being treated with cab, showed good results, none of them having developed diabetes after six months treatment and some of them even showing lower IGF-1 values. So that's why she put us on cab already

His hypothyroidism is under control with thyroid hormone replacement twice a day, and for the hyperaldosteronism we can keep his potassium level within the normal range with potassium supplements also twice a day.

Thanks for sharing the link to the study, I had already discovered the thread and read the study earlier. Google is my new best friend since our Kitty became a complicated case

Small update in the meantime: we restarted cab with 0,4 ml like I announced yesterday and he supported it fairly good. He's not sleepy and only has a bit of diarrhea, but we've seen that before and always keep some probiotics ready to tackle this. I will stick to the plan of giving him cab every other day now and then switching to every day administration. After that and if everything keeps going well, I will start raising the dose until we reach his recommended 1,1 ml every day. But that will obviously not be this week yet

 

[Wendy&Neko]

According to our vet in Ghent, very recent research in the UK with nine cats having acro without diabetes and being treated with cab, showed good results, none of them having developed diabetes after six months treatment and some of them even showing lower IGF-1 values.

Thanks for that update. I do like to keep track of what is happening with acro research. It's especially interesting because the initial RVC (Royal Vet Clinic) small pilot study on cabergoline showed no decrease in IGF-1, one of the reasons they decided not to continue with research with it. Side note, just before they published, our first cat here on cabergoline went off of insulin (in less than 2 weeks), and we had let the researchers at RVC know that there was better experiences out there. That study of 9 is more cats that the original cabergoline pilot study.

Glad to hear Bob is doing better with a small dose. Probiotics is a great idea. If diarrhea continues, you might even want to try s. boullardi - more information here, including dosing.

 

[Howiesmom]

Hi @Bob's Staff . Your username makes me chuckle! Very interesting to read about your kittie! Howie was diagnosed with acro in Jan 2021 and started Cab the next month. I had to help him over the rainbow bridge about 6 weeks ago. He was very diabetic and was up to 57 units of insulin twice a day. By the end, he was down to 3.5 units. I only mention this in case Bob develop diabetes. It took a long time to really take effect, but I never wanted to take him off it as I didn't know what the lack of cabergoline would mean for him. I never tested his IGF-1 again after the initial test but wish I would have. He also had insulin anti- autobodies (IAA) so that also played in with his entire condition and how much insulin he needed. I did test him for HCM but that was negative. When we finally caught his heart murmur, it was already grade 3-4. He also had pancreatitus and pretty significant arthritis which is not uncommon in acro kitties. He got solensia injections monthly. In looking at all his photos in recent weeks, I can see how his bone structure did change, especially in his facial features.

As for physical effects, he did have the GI issues for the first 7-10 days, but then was fine. I gave him his dose everyday. As for sleepiness...hmmm...good question! He was a pretty lazy cat to start with. As he got older, I think he was developing some kittie dementia. It's hard to pinpoint what could have been from medicine and what was old age. He was probably around 13 when he was diagnosed and was somewhere around 17 when he crossed the Bridge. But we don't know for sure as he was a rescue I got in March 2020 as my pandemic pet.

Please keep posting with your experiences. We need to learn more about this wretched disease.

 

[Bob's Staff]

Thanks for that update. I do like to keep track of what is happening with acro research. It's especially interesting because the initial RVC (Royal Vet Clinic) small pilot study on cabergoline showed no decrease in IGF-1, one of the reasons they decided not to continue with research with it. Side note, just before they published, our first cat here on cabergoline went off of insulin (in less than 2 weeks), and we had let the researchers at RVC know that there was better experiences out there. That study of 9 is more cats that the original cabergoline pilot study.

Glad to hear Bob is doing better with a small dose. Probiotics is a great idea. If diarrhea continues, you might even want to try s. boullardi - more information here, including dosing.

Next time I meet our vet at the university clinic, I'll ask more details about this recent study. If the results have already been published, I'll ask for a link to share here I understood from the already available research that cabergoline shows better results when the pituitary tumour is still small and IGF-1 is not yet too high, but different studies have different contexts and in Ghent they told us the small pilot study should be taken with a grain of salt ... I'm really curious now about the details of their recent findings!

Thanks for sharing the link about probiotics. We are using Probiovet (manufacturer: Digamed), which really works wonders here so the diarrhea is under control. Fortiflora was a no go here, Kitty immediately ran away from it, even when we mixed it with food.

 

[Bob's Staff]

Hi @Bob's Staff . Your username makes me chuckle! Very interesting to read about your kittie! Howie was diagnosed with acro in Jan 2021 and started Cab the next month. I had to help him over the rainbow bridge about 6 weeks ago. He was very diabetic and was up to 57 units of insulin twice a day. By the end, he was down to 3.5 units. I only mention this in case Bob develop diabetes. It took a long time to really take effect, but I never wanted to take him off it as I didn't know what the lack of cabergoline would mean for him. I never tested his IGF-1 again after the initial test but wish I would have. He also had insulin anti- autobodies (IAA) so that also played in with his entire condition and how much insulin he needed. I did test him for HCM but that was negative. When we finally caught his heart murmur, it was already grade 3-4. He also had pancreatitus and pretty significant arthritis which is not uncommon in acro kitties. He got solensia injections monthly. In looking at all his photos in recent weeks, I can see how his bone structure did change, especially in his facial features.

As for physical effects, he did have the GI issues for the first 7-10 days, but then was fine. I gave him his dose everyday. As for sleepiness...hmmm...good question! He was a pretty lazy cat to start with. As he got older, I think he was developing some kittie dementia. It's hard to pinpoint what could have been from medicine and what was old age. He was probably around 13 when he was diagnosed and was somewhere around 17 when he crossed the Bridge. But we don't know for sure as he was a rescue I got in March 2020 as my pandemic pet.

Please keep posting with your experiences. We need to learn more about this wretched disease.

Thanks for your reply! I'm sorry to hear that your darling crossed the rainbow bridge Looks like he reached a high age, in spite of his complex situation. You did a great job having taken such good care of him! 17 is still far away for us, we would already be happy if Bob could reach his 13th birthday, since it's already a miracle he reached his 12th a few months ago ... I'm glad to hear you were able to enjoy Howie's company for several more years after his acro diagnosis!

I'm really flabbergasted by the effects of cabergoline on the insulin needs! Amazing how Howie showed such a decrease too!
I see there was not a lot of time between the acro diagnosis and the start of cab ... May I ask if you still remember his initial IGF-1 value? It is true that after a while, when new symptoms occur, it becomes difficult to tell if they are due to ageing or medicine, but it is a hopeful message that it is possible for acro cats with diabetes to survive on cab for several years.

Bob is also on Solensia for two months now, and we sometimes see him rush through the house like a young gazelle now

It is indeed a very evil disease, but it is a positive evolution that some research is being done, even though there is still a long way to go. I'll keep you posted about Bob's evolution and progress!

 

[Wendy&Neko]

it is a hopeful message that it is possible for acro cats with diabetes to survive on cab for several years.

I just went through what cats I could remember, we did have one kitty who was quite young when diagnosed and IGF-1 was just above lower end of range, who lived 4.5 years on cabergoline.

When you are comparing IGF-1 numbers, note that early this year MSU (Michigan State University) changed their assay methodology, and at the same time change their reference range and units type to nmol/L to ng/mL. This means any kitty measured in North America before then will have a different range of numbers than you are likely used to. More current numbers now use the same units type as Royal Vet Clinic does, which may have been where Bob's IGF-1 test was done.

 

[Howiesmom]

Thanks for your reply! I'm sorry to hear that your darling crossed the rainbow bridge Looks like he reached a high age, in spite of his complex situation. You did a great job having taken such good care of him! 17 is still far away for us, we would already be happy if Bob could reach his 13th birthday, since it's already a miracle he reached his 12th a few months ago ... I'm glad to hear you were able to enjoy Howie's company for several more years after his acro diagnosis!

I'm really flabbergasted by the effects of cabergoline on the insulin needs! Amazing how Howie showed such a decrease too!
I see there was not a lot of time between the acro diagnosis and the start of cab ... May I ask if you still remember his initial IGF-1 value? It is true that after a while, when new symptoms occur, it becomes difficult to tell if they are due to ageing or medicine, but it is a hopeful message that it is possible for acro cats with diabetes to survive on cab for several years.

Bob is also on Solensia for two months now, and we sometimes see him rush through the house like a young gazelle now

It is indeed a very evil disease, but it is a positive evolution that some research is being done, even though there is still a long way to go. I'll keep you posted about Bob's evolution and progress!

Howie had an IGF1 test done in Sept 2020 and he was at 83 (normal range at that time was 12-92). That is also when he was diagnosed with IAA. I re-tested him in Jan. 2021 (just shy of 4 months since the last test) and he was at 532. That is when his insulin dosage was in the 50s.

 

[Bob's Staff]

I just went through what cats I could remember, we did have one kitty who was quite young when diagnosed and IGF-1 was just above lower end of range, who lived 4.5 years on cabergoline.

When you are comparing IGF-1 numbers, note that early this year MSU (Michigan State University) changed their assay methodology, and at the same time change their reference range and units type to nmol/L to ng/mL. This means any kitty measured in North America before then will have a different range of numbers than you are likely used to. More current numbers now use the same units type as Royal Vet Clinic does, which may have been where Bob's IGF-1 test was done.

4.5 years is a long time, that makes me hopeful!

Bob's test was done in Belgium at Ghent University, where they measure in ng/ml. I did also notice that other measurements are used in the research, which makes it indeed difficult to compare. I only know that Bob's value was at least 2x the normal value

In the meantime he is still doing great on his 0.5 ml Galastop every other day, so we moved to 0.6 ml now. Don't want to rush things, because I know his body doesn't tolerate big changes anymore and we don't want to have to start all over again when the side effects get too bad ...

 

[Bob's Staff]

Howie had an IGF1 test done in Sept 2020 and he was at 83 (normal range at that time was 12-92). That is also when he was diagnosed with IAA. I re-tested him in Jan. 2021 (just shy of 4 months since the last test) and he was at 532. That is when his insulin dosage was in the 50s.

Wow that's a big change in a few months! Bob's value doubled after several months, but Howie's went totally out of control it seems, way above the normal range. Even though it's difficult to compare when they are measured with different units; in Belgium the upper range is 500 because they measure in ng/ml