Welcome, Guest. Please login or register.

Username: Password:

Author Topic: Addison's Disease & Hypothyroidism - Problems with Medication  (Read 179 times)

JulieG

  • Newbie
  • *
  • Posts: 2
    • View Profile

Hello Everyone,

My name is Julie, and I am hoping that you will be able to help me with some advice regarding my dog's current health situation.

This is rather a long story, but telling it in its entirety is imperative, so that you can get the full picture of what has been occurring.

My dog, Jetta, is fifteen years and two months old. She is a smooth-coated border collie, and she was diagnosed with Addison's Disease at the age of six years. When first diagnosed, she was prescribed Florinef, with Prednisolone given in times of stress. She coped extremely well on this medication.

Then, in 2016, Jetta was moved on to the Zycortal injections, with a daily dose of Prednisolone. She seemed to stabilise quite quickly on the Zycortal but, in 2019, after developing sore skin lesions, she was also diagnosed with Hypothyroidism, and prescribed Thyforon 200mcg (one tablet, twice daily). Her skin condition cleared up over time, and all has seemed to be well-controlled in both her Addison's and Hypothyroidism, until this last six months.

Ever since starting on the Zycortal injections, Jetta has displayed a bit of hind leg weakness when her injection is due (most likely due to the increase in her potassium level, as the Zycortal depleted in her system) but this has always corrected itself within a day or so of her receiving the injection.

Since around October 2020, however, the periods of her hind leg weakness have started to become more frequent, and have been occurring at different times of her Zycortal injection cycle. Instead of it being through an increase in her potassium level though, it has become evident that her potassium level is being pushed down too low, within a few days of her injection being given. This was initially highlighted in January 2021, when Jetta was admitted for an overnight stay in the Pet Hospital (for rehydration and IV potassium supplementation) due to a twenty-four hour period of intermittent vomiting and loss of appetite, which occurred just five days after receiving her Zycortal injection.

Jetta's vet has been very helpful and has worked hard with us to try to resolve this issue. She has spoken with various people at Dechra, regarding Jetta's Zycortal dosage and her symptoms, to which the responses have been: it could be that Jetta's Zycortal dosage is too high; it could be her age and the way her body is processing the Zycortal; it could be the Prednisolone, as that can cause muscle weakness over time. the latter, we felt, would result in constant hind leg weakness whereas Jetta's is intermittent.

Over the course of the last three months, Jetta has had three full blood panels (one in the Pet Hospital and two at her own vet's) and numerous blood tests to check her electrolytes at different stages of her injection cycle. Her heart is healthy and strong. Her blood pressure is normal. All of her blood results have been in the normal range, except for her potassium level, so based on that, we all decided that it would be best to try the low-dosage protocol with her Zycortal injections.

Jetta was originally on 1.65mg per kg (1.10ml of Zycortal) every twenty-eight days. She is now down to 1.07mg per kg (0.71ml of Zycortal) every twenty-eight days. She also has 3mg of Prednisolone daily. Her thyroid medication was one tablet, twice daily of Thyforon 200mcg, however, after a blood test (two weeks ago) her thyroid level was found to be just above the limit of the normal reference range, so her vet reduced her dosage to half a tablet, twice daily of Thyforon 200mcg. (*Please see my update, regarding this, at the end of my post).

Jetta's weight was 16.4kg, but over the last two months she has put on a small amount of weight. She is now 16.8kg.

During her most recent injection cycle, we noticed an overall improvement in her hind leg weakness for around seven days (mid-cycle), however, during the week leading up to her Zycortal injection, her legs began to weaken again. Her potassium level was checked at day twenty-one, and it was only 3.2, but on injection day (at day twenty-eight), it had gone up to 4.0. Her vet gave the injection at day twenty-eight, with another 10% reduction in the dosage.

It is very confusing to us all, including Jetta's vet, as to why her electrolytes are stabilising mid-cycle, but then her potassium level is dipping down again (when it should really be increasing later in the cycle). We are wondering, therefore, if Jetta is still on too high a dose of Zycortal or if the injection is simply no longer working as it should do in her system. If so, would going back on the daily tablets (the generic version of Florinef) be a better option for her, and is this option still available (her vet doesn't seem to think that it is still available)?

We know and understand that Jetta is a senior citizen, but she has no other problems, except for these episodes of hind leg weakness, which is most frustrating for us and for her.

*Update on the recent reduction in Jetta's thyroid medication dosage.

This has thrown up another confusing, but yet interesting, situation. About six or seven days after Jetta's thyroid medication was reduced to half a tablet, twice daily of Thyforon 200mcg, she began to show symptoms of hypothyroidism: lethargy, occasional trembling, and her hind leg weakness got considerably worse. This corresponded with day six onwards of her Zycortal injection cycle, so at first we assumed it was due to the effects of the injection again. However, at day twelve, when she was no better, I decided to put her back on the original dosage of one Thyforon 200mcg, twice daily, to see whether this had any effect. Within twenty-four hours, she was so much better and much stronger on her hind legs. This has now got me wondering whether her problem has been partly due to her hypothyroidism. For many months, even though on thyroid medication, she has had an excessive amount of dandruff and has been losing more fur than usual, as well as the obvious muscle weakness in her hind legs. These symptoms tend to point to her actually not being on a high enough dose of Thyforon (even prior to the reduction), which makes her recent thyroid blood test all the more confusing (just above the upper limit of the normal reference range).

Your thoughts, suggestions and comments would be most appreciated, and thank you in anticipation.

Kind regards to all,

Julie (and Jetta)
Logged

Jo CIMDA

  • Administrator
  • Hero Member
  • *****
  • Posts: 3055
    • View Profile
Re: Addison's Disease & Hypothyroidism - Problems with Medication
« Reply #1 on: April 15, 2021, 08:35:15 PM »

Hi Julie and Jetta

Hormones are such tricky things because they can have a knock-on effect on each other, and sometimes one problem at a time needs to be addressed as opposed to looking at the whole picture.   Also, just because a dog is getting on a bit in years, vets shouldn't think that she is 'an old dog'.  Her blood results and physical health may be better than a dog half her age.  Of course age may play a part, but it doesn't always.

It is acceptable, and can be normal for some, when a dog is on thyroid hormone replacement therapy for the level to be up to 25% above the reference range, and as a dog gets older the dosage sometimes has to be altered according to the clinical signs, so the increase in thyroid meds back to a higher dose seems the right thing to do, and you have seen positive results too, which is good news. The slight increase in weight, and perhaps lethargy and other typical signs of a low thyroid could certainly have been down to the less than ideal dose of Thyforon.  At least, for now, you can take the thyroid out of the equation.

As for the Zycortal, Jetta has done really well to have come off of F-florinef and on to Zycortal without any major problems but again, as dogs get older sometimes the dose may have to be altered according to the blood results and clinical signs. It is also possible that a lower than ideal thyroid level may have had an affect on how the Zycortal is tolerated/used/metabolised etc.  What is her usual sodium and potassium ratio K:Na at day 28, just before the next injection is given? 

The majority of dogs that were started on the ridiculously high dose of Zycortal that the drug sheet still recommends have, over time, been reduced to a much lower level and some dogs that I have known have been stable at  levels 0.5ml every 28 days.  Unfortunately, despite the science, it is often a 'suck it and see' situation and the dose and duration has to be tailored to the individual. I wonder if it is worth checking with the manufacturer if the batch of Zycortal being used is stable and efficacious?

As far as I know F-florinef is still available in Europe but depending on where you live the export to some countries may be impossible.  The generic name is fludrocortisone acetate and this should still be available as an extra label drug.

Now that you appear to have a better result by increasing the dose of Thyforon back to where it was,  perhaps this will allow any remaining symptoms to show a clearer picture of what might need tweaking.   Lots of Addisonian dogs need less than the recommended dose of pred too, so if you and your vet are happy with the thyroid blood results, and the improvement of other clinical signs that are associated with hypothyroidism; and the if the correct Zycortal dose is established and her Addison's is stable, if Jetta still has symptoms of weakness then look at whether the pred need to be reduced and the pred dose optimised.  This can be reduced very slowly over weeks  by 0.5mg reductions to see if it makes a difference.   

Does Jetta have a temperature, are her leg joints warm to the touch, and does she seem to be in pain when she tries to get up?

Jo





 
Logged

JulieG

  • Newbie
  • *
  • Posts: 2
    • View Profile
Re: Addison's Disease & Hypothyroidism - Problems with Medication
« Reply #2 on: April 16, 2021, 08:12:01 PM »

Hi Jo,

Thank you so much for responding to my post, and for your suggestions regarding Jetta's medication issues. You have really helped me to clarify things in my mind, and I feel more confident that we are on the right track to get Jetta's system balanced again.

In answer to your questions:

Jetta has not had a temperature at any time since her problems began. It has been checked on numerous occasions at her vet's and at the Pet Hospital, when she was admitted. It has been normal every time.

Her leg joints are not warm to the touch.

She has no pain when she tries to get up - the weakness obviously makes it more difficult and slower for her, but there is no pain associated with it.

With regard to her usual sodium and potassium ratio on injection day (day 28), I will firstly give you a little background information.
The vet that first diagnosed Jetta's Addison's Disease, and treated her until he retired early and sold his veterinary practice (back in 2017), was very knowledgeable about Addison's. He transitioned Jetta on to the Zycortal, and would only administer her next injection when her Na and K were both very close to the middle of their respective reference ranges, with a ratio of around 30-32. When he was satisfied that Jetta was stable on the Zycortal, he only checked her electrolytes once every three months.

This three-monthly checking regime was continued by Jetta's current vet, who took over her treatment in 2017. She would confirm to us that Jetta's Na and K were in the normal range and, at that stage, we just assumed that she was following the same protocol (with regard to ratio) as Jetta's previous vet. It wasn't until Jetta's problems started, six months ago, that we requested the Na:K ratio every time she had a blood test, and we were very surprised to learn that her current vet had previously administered the Zycortal injection when Jetta's Na:K ratio was 40. We explained to her that we were told (by her previous vet) that the ratio should be much lower before giving the next injection but, after speaking with Dechra, she said that they tend not to go off the Na:K ratio now, but concentrate more on the individual levels of Na and K. I personally feel that the ratio (with Na and K in the middle of their reference ranges) is still of the utmost importance.

Jetta's last four blood results are as follow:

Sodium 147      Potassium 3.9      Ratio 37.69
Sodium 149      Potassium 3.8      Ratio 39.21
Sodium 149      Potassium 4.4      Ratio 33.86
Sodium 147      Potassium 4.0      Ratio 36.75

We will do as you have suggested, and continue to tweak the Zycortal injection down. It makes good sense to see how much improvement there will be in Jetta's hind leg weakness when we reach the optimum dosage for her.

I will update you with Jetta's progress, and thanks very much again for your help and advice.

Kind regards,

Julie and Jetta
       
Logged

Jo CIMDA

  • Administrator
  • Hero Member
  • *****
  • Posts: 3055
    • View Profile
Re: Addison's Disease & Hypothyroidism - Problems with Medication
« Reply #3 on: April 17, 2021, 10:54:52 AM »

Hi Julie

You were so lucky with your first vet.  Changing over suddenly to Zycortal threw everyone into confusion. It wasn't fair on the vets, the owners and definitely not fair on the Addisonian dogs who were being well controlled on F-florinef.   It was a disgraceful thing for the drug company to do and I knew some dogs who didn't survive the transition.

5 years on, the vets should know better, but of course Addison's disease is not seen, or diagnosed often in general practice and the GP vets don't have the experience, and in my experience Dechra are not the most helpful of companies.

I totally agree with you, the K:Na ratio is what I would look at first and then the individual values if there was some concern.  Just looking at the separate values of K and Na, in my opinion, does not take into consideration how the individual patient processes and utilises the replacement hormones.  Hormone replacement therapy is always tailored to the individual, taking into consideration the clinical signs as well as the blood results, and of course ageing.  If the ratio wasn't important  then why, historically,  would it have been such a key indicator in diagnosing and treating Addison's disease?   If the ratio is higher than around 32 then I believe the next dose of Zycortal should be delayed.   I have known some dogs go to over 60 days before the next dose was necessary but that was in the early days of Zycortal.

The reason why I asked about a high temperature and swollen joints is Jetta has a genetic predisposition to autoimmunity and when a dog has had one AI disease there is a chance that they will get another (as with Jetta), so the weakness could have been something like IM polyarthritis or IM myositis, but Jetts'a weakness does seem linked to her hypoT and Addison's and nothing more, and that is good news.

 Thank goodness that you are on the ball!

Jo

Logged