Saturday, December 14, 2013

Treating Small-Breed Addison's Dogs with Low Doses of Prednisone or Prednisolone


My 4-year old Toy Poodle was diagnosed with atypical Addison's disease about 6 weeks ago. She weighs 11.8 lbs and is taking 1.25 mg of prednisolone per day. She is not receiving any mineralocorticoid supplementation (i.e., Florinef or Percortin-V) for now since her serum sodium and potassium levels are in the normal range. We will continue to monitor that because we know that that might change and mineralocorticoids will have to be added to her treatment.

For her glucocorticoid needs, we are using a 5-mg tablet of prednisolone that we cut into quarters to administer a 1.25-mg dose each day. This is extremely tricky, and there is probably never a day that she gets an exact dose because the tablets do not cut without some crumbling.

So I have two main questions:
  1. First, my dog has developed a ravenous appetite and finishes her meals very quickly. Normally, she has a picky appetite. I know that you generally recommend giving these dogs a much lower dosage, and that a lower dosage would be better for her overall health since she will be on this daily dosage for the rest of her life. Should her prednisolone dosage be lowered to help with the appetite issue? 
  2. Second, is there any other tablet or form of prednisolone that would be easier for us to administer to her so that she gets the proper amount each day? The 5-mg tablet just isn't working very well for us. 
Thank you for your help.

My Response:

The glucocorticoid replacement dose I use for prednisone or prednisolone in dogs with Addison's disease is 0.1-0.2 mg/kg/day. So at 11.8 pounds (5.4 kg), that calculates out to be only 0.5 mg/day, up to a maximum dose of 1.0 mg/day. So if you are giving your small dog 1.25 mg/day, that means you are giving too much of the drug. That would certainly be enough to induce iatrogenic Cushing's disease, as reflected by the increased appetite.

In dogs, prednisone is converted to prednisolone within the body. So basically, these two glucocorticoids can be used interchangeably.

I would try to lower the daily prednisone/prednisolone dose down to 0.5 mg each day. Administrating too much glucocorticoid will cause increased hunger (as you see in your dog).  Overdosage of prednisone, prednisolone or any other glucocorticoid can also lead to lethargy, weight gain, enlargement of the abdomen, muscle atrophy, and muscle weakness. Decreasing the dose of the prednisone or prednisolone should help prevent any of these problems.

Fig. 1: Prednisone is available as a 1-mg tablet
Fig 2: PrediapredOral prednisolone
liquid (1 mg/mL) 
Prednisone tablets are available as 1-mg and 2.5-mg sizes, which can be helpful in dosing small to medium-sized dogs (Figure 1).

In addition, both prednisone and prednisolone are available as a syrup/oral liquid or solution, available as a 1 mg/mL concentration (Figure 2).  Examples of liquid prednisolone products include Pediapred® (Celltech Pharm); Millipred® (Laser); Orapred® (Sciele); Veripred® 20 Hawthorn); and Flo-Pred® (Taro). For prednisone, Intensol® Concentrate (Roxane) oral solution is available.

All of these formulations are human-labeled products so your veterinarian may not be familiar with them. Your local pharmacy will know about them, however.

Either way, I'd get either the 1-mg tablets and give half a tablet a day. Or use a liquid formulation (1 mg/mL) and give 0.5 mg (1/2 mL per day).

References:
  1. Plumb, DC. Plumb's Veterinary Drug Handbook. Seventh Edition, Wiley-Blackwell. 2011.

3 comments:

Denise Beutel said...

Dr. Peterson,
I was the one that wrote to you in December regarding our 4 year old poodle, Bailey. My vet still believes that the 1.25 mg of prednisolone per day is fine, but she did order the 1 mg prednisone if we wanted to try it. Bailey is still eating her meals too quickly and I have noticed that she has become very "barky". I have the 1mg tablet of prednisone from our pharmacist. I want to move her to it now, then split it and give her .5 mg per day, however I have been stupidly putting it off because I read that prednisolone is better then prednisone in the long run on her liver. Is this true? What is the long term effect of these two glucocorticoids and what is your expert opinion on giving her a liver support to help her? Thank you again.

Dr. Mark E. Peterson said...

Prednisone is converted directly to prednisolone so there is no difference between the 2 drugs in dogs.

Neither of these glucocorticoids is bad for the liver UNLESS you are giving too much of the drug. That's why we want to use the lowest dose possible.

sowpath said...

thanks