Is it ok to take ponstan (ponstal in the us) if you have asthma?

Yes. Ponstal is a type of NSAID like motrin. Unless you are allergic to the medication it won't cause your asthma to flare.
Most Likely. Mefenamic acid is used to relieve mild to moderate pain, including menstrual pain. Mefenamic acid is in a class of medications called nsaids. It works by stopping the body's production of a substance that causes pain, fever, and inflammation. If you have no problems with nsaids and flaring of your asthma, then you are safe to try it. Have u ever taken aleve, (naproxen) motrin, aspirin, ibuprofen?