Summary. Gastritis is found among people who take Naproxen, especially for people who are female, 60+ old , have been taking the drug for 1 month, also take medication Nexium, and have Rheumatoid arthritis. Gastritis is an inflammation, irritation, or erosion of the lining of the stomach. It can occur suddenly (acute) or gradually (chronic). What Causes Gastritis? Your recovery from chronic gastritis depends on the underlying cause of the condition. If chronic gastritis continues without treatment, your risk of stomach ulcers and stomach bleeding increases. Common pain relievers — such as aspirin, ibuprofen (Advil, Motrin IB, others) and naproxen (Aleve, Anaprox) — can cause both acute gastritis and chronic gastritis. Using these pain relievers regularly or taking too much of these drugs may reduce a key substance that helps preserve the protective lining of your stomach. Naproxen is a nonsteroidal anti-inflammatory drug (NSAID) used to treat pain and inflammation for many medical conditions. It is the active ingredient in the over the counter medication Aleve. Irritants — Chemical and environmental irritants can damage the stomach lining and cause gastritis. Common irritants include alcohol; cigarette smoke; aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen ( Advil , Motrin and others) and naproxen ( Aleve , Naprosyn and others). Have a Question? Talk to a Specialist! Call 800.739.7706 Contact Us Now! Common pain relievers — such as aspirin, ibuprofen (Advil, Motrin IB, others) and naproxen (Aleve, Anaprox) — can cause both acute gastritis and chronic gastritis. Using these pain relievers regularly or taking too much of these drugs may reduce a key substance that helps preserve the protective lining of your stomach. Can Naproxen cause Gastritis? Gastritis is a known side effect of Naproxen. Complete analysis from patient reviews and trusted online health resources, including first-hand experiences. - Page 2 Gastritis is a known side effect of Naproxen. The outlook for gastritis depends on the underlying cause. Acute gastritis usually resolves quickly with treatment. H. pylori infections, for example, can often be treated with one or two rounds.