Imuran for IMPA

[betsytesta]

Hello.  I haven't been on here in quite a while.  My Doberman was diagnosed with IMPA in March of 2017.  It has been up and down, and she has had a few relapses since the diagnosis.  Her previous relapse was at the end of December, and then she relapsed a little over a week ago; she was on 150mg Cyclosporine.  We had already weaned her off 5mg of Pred 6 weeks before.  She was doing really well, and we were all set to start decreasing the Cyclosporine to 125mg, and she crashed.  There's just no rhyme or reason to it... unfortunately, the vet who has been treating her went on maternity leave.  I was able to communicate by email before she left, and she set up an appt. at the hospital with a different vet for me.  Our vet, who we LOVE, instructed me to put Ahnka back on 20mg of Prednisone and keep the Cyclosporine at 150mg.  The new vet prescribed Imuran, 50mg, once every 48 hours.  This is in addition to the 25mg Pred and 150mg Cyclosporine per day.  Does anyone have experience with this drug?  It sounds like it has a lot of side effects.  I'm so paranoid about starting a new drug that wasn't approved by the vet who has been treating my girl for a year!

Betsy

[Jo CIMDA]

Hi Betsy

I am sorry you are having problems with stabilising Ahnka's  IMPA.  Clearly the cyclosporine isn't bringing the disease under control and achieving remission.

IMPA responds very well to prednisolone but it has to be in immunosuppressive doses and I would think that a Doberman would need considerably more than 20mg a day. This can only be, at best, an anti-inflammatory dose of pred.  (Anti-inflammatory dose prednisolone:  0.5-1mg/kg/per day, Plumb's Veterinary Drug Handbook, 8th Edition) 

If Ahnka were mine I would want her to be on an immunosuppressive dose of prednisolone at 1mg/kg/12hours and follow a good immunosuppressive drug protocol such as Prof. Michael J Day's.   This increased dose should make a difference very quickly and as she is already on cyclosporine you may be able to reduce the preds a little sooner than usual, however I do wonder if the dose of cyclosporine is adequate?   

Cyclosporin and other cytotoxic immunosuppressive drugs have their role to play but in my opinion they do not work as efficiently as prednisolone and they should be used as a combination drug to support the immunosuppression achieved by pred, and not a primary drug. 

Plumb's Veterinary Drug Handbook 8th Edition:  Cyclosporine as an immunosuppressive dose:  Empirical doses usually range between 3-6mg/kg twice a day or 5-7mg/kg once daily. 

If Ahnka is anything like the usual weight of a Doberman bitch then I doubt that either the prednisolone dose or cyclosporine dose is sufficient to bring the disease into true remission, and this is very likely to be the reason why she relapses.  The treatment protocol for AI disease is very clearly defined in as much as the drugs have to be in immunosuppressive doses, and for the correct duration of time, and tailored to the individual taking into account of adverse effects of the drugs and resolution of the disease. This is the only way to achieve long term remission.   IMPA is one of the AI diseases that carry an excellent prognosis if the correct treatment is received.

The drug Azathioprine has been used as an immunosuppressant in 'combination' therapy with preds for decades and it works very well.  It has no worse long term side effects than cyclosporine, but does she need this additional drug? I am not convinced?   Personally, I prefer Azathioprine to cyclosporine but as Ahnka has already been on Cyclosporin, I would be inclined to continue with this combination drug.   They are both cytotoxic drugs.  I don't see the point in adding another drug when the dose of drugs already being used isn't sufficient to bring this disease under control and into remission.  It is far better to give correct doses before trying something else at a lower dose than recommended.

Plumb's Veterinary Drug Handbook 8th Edition:   Azathioprine:  General recommendations are:  2mg/kg/once daily for 1-4 weeks.  Then the dosage is reduced to 0.5-2mg/kg every other day.  After treatment has begun there is a lag period of at least a week and as often as long as 3-5 weeks is required before there is significant clinical immunosuppressive efficacy.

The above quote is from an extremely reliable source, and is very current information, but when my dog was treated with Aza over 20 years ago, and until very recently, it was considered that it takes at least 10 days to have any effect and did not reach its full potential for 6-8 weeks.  Is this a suitable drug for Ahnka at this stage of her treatment?

If Ahnka were mine I would want the preds to be raised to the correct immunosuppressive dose, unless there is very good reason not to, and leave the cyclosporine as it is (because it is a secondary drug to the pred) or the cyclosporine could be increased as well but if the pred dose is correct then I doubt this will be necessary. Don't forget a gastroprotectant!

Jo

[Jo CIMDA]

P.S.

When Cyclosporin was first used as immunosuppressant, it was recommended that the blood levels were monitored to see that the Cyclosporine dose given had achieved immunosuppressive levels.  This is not done very much these days and perhaps it should be because what is the point in giving a drug if the dose is not enough to have the desired effect?

Jo

[betsytesta]

Thank you!!  Most vets here know little or nothing about AI diseases.  It's really frustrating.