Is It Safe To Use Apo-Naproxen For Pain Relief?

I have been prescribed Apo-Naproxen in the past for relieving inflamation/pain and was wondering if there was a non-prescription product that I could buy? Advil works if taken regularly but I found that I am not consistent (don't want to take all the time and is slow to kick in) but Apo-Naproxen 250mg taken just once can help into more than one day!