# Vidalta



## jonesp1 (May 30, 2008)

Hi,

My cat got diagnosed with a thyroid problem 4 weeks ago. She was given 10mg vidalta tablets to be taken once a day. Her first checkup after two weeks was ok. Her heart rate had slowed and her weight had stabilised.

Then on week 3 she has suddenly gone off her food. She may try eating a bit but doesn't seem particularly interested in eating.

Took her to the vets today and she had lost quite a bit of weight and they did a full blood works again and everything looks ok. T4 count was 28. 

The vet suggests it could be her teeth hurting as they aren't the best and suggests putting her under to take out the bad ones. He also wants to do an ultrasound of her belly. 

While I think both are probably a good idea I cant help but look at the obvious things that have changed. This being the tablets.

I have read a lot about vidalta and its side affects.

Has anyone got any experiences with this drug?

My thinking is to stop the drugs and see if she improves. The vet thinks any problems with the tablets would have been seen in the first couple of weeks.???

Any help would be appreciated. Sorry for the long post.

Thanks
Paul


----------



## Ianthi (Oct 21, 2008)

Yes, I've got experience of Vidalta and I've heard of many other who've had the classic side-effects of inappetence which you've experienced-so I'm at a loss to understand why your vet hasn't! What was the T4 on diagnosis?

What your vet is saying is totally illogical here since this is exactly the point ( when T4 is within normal range) when problems can occur since essentially the cat is now being overdosed! These 10mg tablets are far too strong in most cases. In addition, for some time now the veterinary (experts) world has recommending lowering the T4 _gradually_ in order to give the organs time to adjust to the decreased metabolic rate-something a lot of general vets appear to be ignoring/unaware of when prescribing initial high doses of these medications. I see if I can dig out the link on VIN.

If I were you ( please don't stop the medication completely though as this condition needs to be controlled) I'd forego all the tests and halve the dose from now on! Do keep an eye on clinical signs though. You may find, however that she's better suited to Felimazole the other medication.

I'd also recommend you join the Yahoo HyperT group where I'm sure (I know) you'll hear much more about Vidalta and these side-effects! It's also an excellent source of advice and information!

feline-hyperT : A support list for people whose cats have been diagnosed as hyperthyroid (hypothyroid also welcome).

I hope halving the dose results in increased appetite!


----------



## jonesp1 (May 30, 2008)

Many thanks for your reply.

Just to give you some history.

Buttons is a 15 year old female moggy. Has had diabetes in the past but hasn't been on insulin for over a year. 

Dec 2012 - general check up. Vet suspected problem with Thyroid but said will test T4 in a months time to confirm.

Jan 14th - Full blood test indicated raised T4 levels. (I think 94 but would have to confirm). Raised heart rate also on this visit. Loss of weight also.

Prescribed Vidalta 10mg 2 weeks worth.

5th Feb - Back for check up. Heart rate had lowered and weight had remained the same. 2.62kg. Good news. Got some more Vidalta on this visit.

11th Feb - noticed Buttons not eating properly and turning her nose up at everything apart from whiskers temptations. I was able to also feed her some sheba but she would only pick at it.

Took her to the vets today (16th) as she wasn't eating normally still and I could tell she wasn't herself. Slightly lethargic.

Vet said heart rate was still low which was good but weight had gone down to 2.30kg. (I am not sure if the weight loss is due to a problem or just because she had hardly eaten anything)????

Vet did full blood test that indicated T4 levels were 28 and everything else was completely fine. As everything was fine he recommended dental work to take out problem teeth and ultra sound on her stomach. $$$$$$

I did mention to the vet about side affects of Vidalta but he insisted they would have showed themselves quite soon after taking them.

I haven't given her a tablet tonight and she has just polished off a load of chicken breast.

My initial thought was to cut out the tablets to see if she returns to her normal self. If she does then we know its Vidalta. Is allowing her T4 levels to temporarily increase dangerous? Also how long until the Vidalta would be out of her system. Is it ok just to cut the tablet in halve to halve the dose? I had read you couldn't do this as it was a slow release drug?

I didn't get a chance to mention this idea to the vet and am also surprised he hasn't thought it could be the tablets.

I look at things logically. The probability of newly taken tablets causing a problem or she has developed a new underlying illness that hasn't been detected by blood tests. Surely the odds are that its the tablets.

Although I'm no vet 

Thanks again for all your help.

Paul


----------



## HannahKate (Jun 6, 2010)

Please don't go breaking the tablets in half. They are designed to be given whole and are less effective when crushed or broken. A lot of tablets are coated with different substances to allow them to reach a specific part of the digestive tract before being broken down. 
Vets may suggest every other day dosing but I would call them first to check that they think that would be ok and when to do a repeat blood test to make sure that the levels are still ok.


----------



## Ianthi (Oct 21, 2008)

You with a T4 of 94 I would definitely have started on a much lower dose. The current (veterinary) recommendations are 1.25 Felimazole twice daily. As it stands 10mg Vidalta (carbimazole which is metabolised to methimazole by the liver) equates to 6mg Felimazole!

Ideally, assuming her appetite is normal she should have put on weight once on the medication as this slows down the metabolic rate! Incidentally, the elevated heart rate seen with hyperthyroidism is for the opposite reason-an increased one. The weight loss now isn't that significant, so as long as she eats from now on (and on the lower med she should) it should increase! Incidentally, any articles I've read in the past have said that side-effects can develop within the first three months.

Frankly, I would be far more concerned if the T4 decreased on the higher dose (you really need to avoid hypoT at all costs) than an increase which may or may not happen. You'd know anyway, because her older, pre-treatment clinical signs would return. At any rate there's no point in having a medication that causes inappetence.

Paul, do join that group by the way! They're all currently dealing with cats with HT and have collective experience of all types of medications/treatments.

Have you thought about the L131 treatment?


----------



## jonesp1 (May 30, 2008)

Hi,

Yes I joined the group looks helpful thanks.

I have looked into the iodine treatment but just not sure about sending her away for a month. There is one locally in Canterbury Kent.

I will find out her exact t4 level on the first appointment tomorrow. 

So shall I talk to the vet about getting her on the other drug to treat this as vidalta only comes minimum 10mg?

I wont give a tablet tonight and will see how she is in the morning.

Cheers


----------



## Ianthi (Oct 21, 2008)

Oh yes, forgot to mention this but I know of one vet who called the manufacturers (Vidalta) and they said it was OK to split the tablet, which lasts for 24 hours so best to give same time each day. If no success re appetite, then I'd discuss the Felimazole, then.


----------



## Cats cats cats (Feb 4, 2011)

Ianthi said:


> Oh yes, forgot to mention this but I know of one vet who called the manufacturers (Vidalta) and they said it was OK to split the tablet, which lasts for 24 hours so best to give same time each day. If no success re appetite, then I'd discuss the Felimazole, then.


I also called the manufacturer ( some years ago now , maybe 3 years ) to confirm whether it was ok to cut these and it is . They are time released I believe but cutting ( as opposed to crushing up ) is fine  the manufacturer said they could not advise me as I am not a veterinary professional , but confirmed in not so many words , that it is indeed fine to cut them 

My angel black ( R.I.P ) suffered loss of appetite when he first went on vidalta so after confirming it was ok to cut the tablets , I reduced his dose to half a tablet ( so 5mg ) and he did a lot better and his appetite returned 

Hope this helps


----------



## Severus (Nov 6, 2011)

You can crush Vidalta, but then it has to be given twice daily (delayed release is part of the reason for the coating). If you wish to halve the dose it is given every other day. But I would consult with your own vet before making any changes to the treatment.

Starting with 10mg daily is standard for hyperthyroid cats. Blood values drop within about 3 weeks if the dose is correct. A value of 28 is still borderline high, but is probably adequate to maintain long term.

If you stop treatment I would expect her appetite to increase as the hyperthyroidism takes hold again.

We sometimes see vomiting and reluctance to eat with both Vidalta and Felimazole, if it occurs in the first few months it usually either passes by itself, or sorts itself after a dose reduction. If it occurs after many months of treatment sometimes it can be a sensitivity to the tablet itself.

I would be concerned at further weight loss, and would now be wondering if treating the thyroid has unmasked another disease process that was being kept under control by the increased metabolism (e.g. kidney disease).

(I am a vet).


----------



## jonesp1 (May 30, 2008)

Hi,

She had the full blood works and everything came back fine including kidneys.

She really isnt acting like herself and seems quite lethargic.

is it safe to see if she returns to her normal self with out the meds to establish if this is a side affect of the drug or an underlying medical condition

Cheers


----------



## Ianthi (Oct 21, 2008)

Severus said:


> .
> 
> Starting with 10mg daily is standard for hyperthyroid cats. Blood values drop within about 3 weeks if the dose is correct. A value of 28 is still borderline high, but is probably adequate to maintain long term. .


Yes, but not all surely? Apart from the low-dose start recommendation, a cat with say an initial T4 of 80 shouldn't be prescribed a dose this high? What we found on the HT Forum was, regardless of T4 on diagnosis, that feline response rates to methimazole were variable to say the least! In addition with Vidalta a large number of cats went hypothyroid with the (consequent impact on renal levels) and had to spend a few days of IV at the vets! Of the two medications, V was the least popular in terms of adverse reactions and high (starting) dose levels.

Actually, while I remember here's that VIN article I referred to earlier!

Feline Hyperthyroidism - WSAVA 2003 Congress


----------



## jonesp1 (May 30, 2008)

Hi,

Thought I would give you an update. This might be a coincidence but she seems much brighter this morning and has eaten most of her cat food and a little bit of chicken. I doubt this can be because I didn't give her tablet last night but you never know.

I am going to speak to the vet today and see if I can get her on Felimazole at a lower dosage. 

My question is can her recent weight loss be simply down to her not eating a lot for a week?

What are the best foods that cats can't resist that will build her up. Hate seeing her so skinny. Poor girl.

She can't resist plain chicken breast - is this ok along with cat food?

Cheers
Paul


----------



## Paddypaws (May 4, 2010)

If your vet does change you over to Felimazole, the instructions on the pack do also state that this tablet must not be cut! This advice does not appear on US packaging, and is actually to protect us humans from the effect of the drug. At my request my vet checked with the manufacturer and we were told that it is in fact safe to cut the tables and indeed Felimazole should be given BID (twice a day) for best coverage.
The last time I looked into the Radio iodine treatment I was told that the hospital stay could be as short as 2 weeks as long as there are no women of child bearing age in the household and that close contact with the cat is avoided in the first few weeks at home (ie, don't let the cat sleep on your pillow with you! )
If she loves chicken breast then I would give her as much as she wants supplementary to her regular cat food.


----------



## Ianthi (Oct 21, 2008)

jonesp1 said:


> Hi,
> My question is can her recent weight loss be simply down to her not eating a lot for a week?


Well, yes I'd imagine it must have something to do with it but the question is why her appetite was affected in the first place? I'm glad to hear it has returned I think transitioning over to Felimazole is a good idea where hopefully appetite won't be affected. I know with mine, I saw a marked difference (weight gain) and reduction in clinical signs soon after treatment had begun.

I've copies the Vidalta datasheet in case you find it useful!

NOAH Compendium of Animal Medicines: Vidalta 10 mg & 15 mg prolonged-release tablets for cats - Clinical particulars


----------



## jonesp1 (May 30, 2008)

Hi,

Quick update. Buttons hasn't had her tablet for the last 2 nights and she seems back to her old self and seems quite lively.

She ate all of her breakfast this morning along with some chicken.

I understand this might be due to her T4 levels now rising but surely this is an indication that the Vidalta didn't quite agree with her?

Am ringing the vets this morning to get her on the other drug.

Cheers
Paul


----------



## Ianthi (Oct 21, 2008)

jonesp1 said:


> Hi,
> I understand this might be due to her T4 levels now rising but surely this is an indication that the Vidalta didn't quite agree with her?
> 
> Am ringing the vets this morning to get her on the other drug.
> ...


Based on my own knowledge and experience of it, I would say yes in terms of the dose being too strong! Hope the Felimazole is better!


----------



## jonesp1 (May 30, 2008)

Spoke to the vet and can pickup Felimazole later today.

He recommends 1 2.5mg tablet twice a day.

Her T4 value initially was in the 90's and is now 28 (well a few days ago while she was on Vidalta)

Is 2.5mg twice a day correct as if we are thinking the 10mg Vidalta was too high then I think that equates to about the same as the Felimazole 2.5mg once the liver has done its thing.

I hope that made sense.

Thanks for everyones help again.


----------



## jonesp1 (May 30, 2008)

Hi,

6 days on from stopping her Vidalta Buttons is eating great and putting on weight (i think).

She weighed in last saturday at 2.30kg so going to get her weighed tomorrow so I can then start her on the Felimazole and have a weight to check against.

I am going to give it 3 weeks assuming she doesn't show any signs of problems and get her blood retested for the T4 levels.

Shall I start on 2.5mg twice a day or less than that?

Thanks
Paul


----------

