Is naproxen related or similar to naprelan?

Yes: Naprelan (naproxen) is an extended-release forumla of Naproxen purported to have less stomach irritation. Of course it is 100's of times more expensive and probably dosen't appreciably lower the risk of GI complications. Also, all nsaid's like Naproxen slightly increase the risk of vascular complications such as stroke, heart attack and high blood pressure.

Similar: When compared there is a difference: mucosal biopsy scores and endoscopic scores were lower in the subjects who received naprelan® tablets. In another study there were significantly fewer duodenal erosions seen with naprelan® tablets than with either Naproxen or aspirin.