You were brave to test yourself that way. I am glad, though, that you did track down what was the problem. I had a similar experience with a drug. I ended up being sent to a neurologist, but my primary care doc was the one who found the culprit: lamictal, of all things!

She said long-term use can be associated with what I was experiencing because I had developed a toxic level in my body. I had never read or heard that before.

I hope you did report your symptom, so it can be added as a possible side effect.

In my case, thing is, no one knows the long-term effects of many drugs, since the subjects in the studies aren't followed very long.