Paradoxical reactions are part of the study within PGx (pharmacogenetics) and one supposition is that some of us have a genetic component that causes this type of reaction. That many ppl don't get the reaction the drug companies expect is another reason for this field. PGx began back in the late 50's so the study of medication action/reaction is nothing new Stick to your guns, it is SO worth it to have something to take to help.

BTW I went to my allergist and was tested and took allergy drops to be able to take Robaxin years ago. Alas I became too sensitive to continue. (It's possible the titration dose increased my sensitivity while allowing me to not react. It finally came down to not being able to cover me for the sensitivity.)