information needed about Vidalta tablets

[CarolM (Wendolene)]

I’m so sorry about your loss Lisa.    

I’ve thought long and hard about replying to this thread but have finally decided that I must.  I firmly believe that what happened to Smudge was a result of the treatment with Vidalta and I’m surprised your vet didn’t realise it sooner.  Haematological side effects (including thrombocytopenia which is reduced platelets) are well documented with carbimazole (the active ingredient).  That said, they are generally mild, but severe reactions are not unknown and I would have expected your vet to do a blood test at the first sign of problems and withdraw the drug if necessary.  As the reaction was so severe this might not have saved Smudge but I would certainly have expected your vet to go down that route.

As regards the lesions on Smudges head, did these just appear or were you aware of her scratching herself?  Pruritus (itching) of the head and neck is again well documented in cats taking carbimazole or felimazole (carbimazole must first be metabolised to felimazole which is the pharmacologically active compound).  This causes the cat to scratch and produce excoriations (lesions).  Once this has happened, spontaneous resolution is uncommon and it is usually necessary to withdraw the drug. 

I do hope you get some answers following the manufacturer's discussions with your vets.  Its so hard to lose a beloved furbaby and if you feel the treatment you gave them may have been a contributory factor then its so much more painful.  I hope you can find peace. 

[Fire Fox]

  So sorry you come to Purrs in such sad circumstances. 

Vidalta is a trade name the drug itself is carbimazole which has been used in humans for decades, so there will be several pharmaceutical companies making this drug. For that reason I'd suggest you plug the drug name into Google as all published research will refer to the drug itself, as will reports of severe side effects, toxicity, allergic responses and guidance on how frequently blood tests should be carried out. I found references to changes in red blood cells, white blood cells and platelets very quickly.

Be aware that in human medicine relatively little time is spent on pharmacology and therapeutics, so student doctors are inadequately prepared for prescribing. Hence we have phamacists and many sources of reference. I suspect the level of preparation will be much the same in veterinary medicine as they really do need to be 'all rounders'.

My last thought is do you have pet insurance? Is there any chance the vet was trying to be conservative in carrying out x-rays and running blood tests in order to save money so care could continue? You may wish to request for a copy of all Smudge's notes in case there is any attempt to cover up an error. 

[clarenmax]

My boy Max was on Vidalta with no ill effect, but that's not to say that your baby isn't suffering a reaction to it 

I hope the vets can give you some definitive answers soon Lisa, you must be out of your mind with worry 

Sending tons of positive vibes your way xx

[Desley (booktigger)]

As I said on the other thread, your vet needs to report this, as it may turn out to be a side effect they dont know about, and unless things get reported, they wont know. Good luck

[Gillian Harvey]

Hi Lisa, I don't have any experience of Vidalta, my cat Elsa was on Felimazole for hyperT, but just wanted to say how sorry I am to read about poor Smudge and I hope you get some answers 

[lisa andrews]

I am looking for some help from people who have experience of their hyperthyroid cats being on Vidalta tablets. My cat Smudge was put on Vidalta about 6 weeks ago, she initially perked up and seemed to be back to her normal playful self but this only lasted a week. After that she became withdrawn, and started suffering from lesions on her head. My vet saw her and prescribed a steroid injection to clear the skin up. This did clear the skin up for awhile, but by the time she went back for her 3 week blood test her head was again covered in lesions and looked very sore. The vet gave her a long acting steroid and advised not to come off vidalta as smudge would overcome this problem as it was a settling in phase of the tablets. She was reluctant at first to say that it was a reaction to vidalta but eventually agreed to report it to the manufacturer. Last Wednesday (6 weeks after being put on vidalta) I saw smudge laying in the garden, when i went to get her in i noticed she was hemorrhaging from her nose and mouth. She was also very unstable on her back end and her tail was limp. I took her straight to the vets who advised to take her home and keep her calm, if she was still poorly in the morning they would admit her for an xray. They could not find any body trauma. I mentioned vidalta, and was told it was impossible to say whether this could be linked. 4 hours later the vets admitted her into the hospital as her bleeding had got worse and was now coming from her back end as well. They did xrays straight away but found nothing untoward. Next morning i got a call to say she was going downhill rapidly, they needed to do blood tests but couldn't get blood as she was bruising badly and her veins kept collapsing. They managed to obtain some blood (not sure where from as blood tests were impossible) and once it was examined they could not find a single clotting platelet. My vet admitted that she had never seen this before. I went straight in and they discussed blood transfusion, but she was too weak to be transferred to a hospital that could do it. It was decided that the kindest thing to do was to put her out of her suffering. I got a feeling from the vet that vidalta was a potential cause. I spoke to the vet who originally prescribed vidalta and she was very defensive. I am in talks with the manufacturers and am awaiting their vet to call me once she has discussed the case with my vets.
I would appreciate any feed back on vidalta tablets both good and bad, and do not wish to scare anybody whose cats are on these tablets as nothing is confirmed.
Thank you for taking the time to read this.
Lisa