Sawa, these are questions you need to be asking your doctor. We would be guessing. Also, you need to let your doctor know what is happening with the meds, too.
I took over-the-counter ibuprofen for years and never had a problem until recently. But, I always took it with food to help protect the stomach. The anti-inflammatories are NSAID's and can cause bleeding ulcers and other problems so you do need to be careful.
Here is good info about Arthrotec.
http://www.drugs.com/arthrotec.html
By the way, did you read the post I wrote called Something That Has Been Helping Me Lately? It's further down on the first page of the forum...at least right now it is. This product is an alternative product that is all natural and really has no side effects. I'm using this with success. You might check this out, print info about it, and talk to your doctor. It works very much like ibuprofen but without the nasty side effects.
Sherrine