Bunny and Wendi – Page 4 – Second Chance AIHA Dogs

Keymaster

Hi Bunny

I’ve had a look at PROIN (phenylpropanolamine hydrochloride) – it is a sympathomimetic amine closely related to ephedrine. It has been withdrawn for human use due to it causing haemorrhagic stroke, but is still used for incontinence in dogs as it does not have the same effect as it does on humans. It is FDA approved for use in dogs of course. Depending on the dose, it can increase blood pressure & decrease heart rate in dogs & I noted it can cause temporary (transient) elevations of platelet count, HCT , Hg & RBC count and serum ALT. It also says use with caution in dogs with diabetes.

Have a look at http://www.prnpharmacal.com/pdfs/Proin-FullPackageLabel.pdf

“Changes to hematology and serum chemistry were not considered clinically significant or related to treatment. The most commonly reported side effects were: emesis, hypertension, anorexia, weight loss, proteinuria, and behavioral changes”

In the animal safety studies section it says:

“In a separate tolerance study, 6 healthy female Beagle dogs were administered PROIN at 20 mg/kg body weight (10 times the recommended dose) twice daily for 21 consecutive days. Mean systolic blood pressure was increased in the 10X group compared to the control, but mean values were within the normal range for both groups. Mean diastolic pressures were above the normal range on days 7 and 21 for the 10X group, and day 14 for the control. The 10X dogs had hypertensive mean MAP values on days 7 and 21, whereas the control dog mean MAP values were in the normal range. There was a trend in 10X dogs for lower heart rates following initiation of PPA treatment. Four of 6 dogs in the 10X group had heart rates below the normal range on day 7, whereas none of the control dogs did. The 10X group dogs had increased hematocrit, hemoglobin, RBC counts, urine specific gravity, and water intake consistent with transient, sub-clinical dehydration that occurred shortly after PPA treatment was started. All 6 dogs in the 10X group vomited at least once during the treatment period, whereas only 1 of the control dogs did. Most of the vomiting episodes took place within 1 hour of dosing. Mean platelet counts were also higher in 10X dogs on all 3 exam days; mean values were above the normal range on day 7, with individual values up to 1.5X ULN. The 10X group had a higher mean serum ALT value on day 7 than the control. Mean ALT values for both groups were in the normal range on all 3 exam days, but 2 dogs in the 10X group had ALT values up to 1.4X ULN on day 7; these elevated values were transient, and all dogs had normal ALT values on days 14 and 21. For either study, there was no evidence of chronic hypertension-induced target organ damage; there were no clinical findings attributable to PPA on the ophthalmic exams, electrocardiogram evaluation, or gross necropsy and histopathology.”

Please note that the dose was up to 10 times the recommended dose in that study. I hate reading animal research like this, but sadly this testing has to be done for FDA approval to be given.

I think you should report what has happened to Wendi to the FDA just in case the proin has some relevance – I presume you can do this via your Vet? Even though there is no mention of AIHA/IMHA, there obviously is an effect on serum chemistry & you are right to be suspicious.

Hope this helps – keep on getting better & better Wendi!

All my best wishes, Sheena

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