Joanne-
I cannot concur with C1's advice. I do not think taking a pill to counter the side effects of another pill is wise.
I do not agree with the information that you received from your pharmacist.
The best I can tell is that your medication has not been changed in theory. Only the manufacturer has been changed. (Both are mixture sof T3 and T4.)
There certainly could be some difference in the amount of each hormone in the pill depending upon the manufacturer. I would think that you are getting a larger proportion of T3 in what you are taking now compared to the Amour thyroid and that this is responsible for your symptoms.
Jay