Individuals using one of the UK’s most frequently prescribed painkillers should know about a rare side effect that can cause a severe burning sensation in the stomach. While this medication is widely used and taken regularly by many, health experts have now issued a warning regarding this potential reaction.‘Burning Stomach’ Warning Over This Common PainkillerNaproxen is a non-steroidal anti-inflammatory drug (NSAID), part of the same group as ibuprofen and aspirin. It helps reduce pain, inflammation, and swelling in muscles and joints. Doctors may prescribe it in tablet or liquid form for conditions like rheumatoid arthritis, osteoarthritis, gout, and menstrual cramps. It’s also used to treat certain muscle or bone problems, including back pain, sprains, and strains. The duration of treatment can vary, some people only need a few days, while others may require longer-term prescriptions. If you take naproxen for an extended period, your doctor may also prescribe medication to reduce the risk of side effects.According to the NHS, your naproxen dose depends on why you are taking it, your age, liver and kidney function, and how well it relieves your symptoms. Older adults and people with heart, liver, or kidney issues usually receive lower doses. For children, the dose is calculated based on weight.Naproxen Side EffectsLike all medications, naproxen can cause side effects, though not everyone experiences them. Common issues, affecting about 1 in 100 people, include:ConfusionHeadacheRinging in the earsVision changesDrowsiness or fatigueDizzinessSkin rashesIf any side effect persists or causes discomfort, speak with a doctor or pharmacist. In rare cases, naproxen can lead to severe stomach problems, such as intense indigestion, heartburn, or abdominal pain, which may indicate an ulcer or inflammation, according to the NHS.Naproxen: NHS Issues Warning Over NaproxenThe NHS website claims: "Your doctor may tell you not to take naproxen if you have a stomach ulcer or you have had one in the past. If you need to take naproxen but are at risk of getting a stomach ulcer, your doctor may prescribe another medicine for you to take alongside naproxen to protect your stomach.”The most common symptom of a stomach ulcer is a burning or gnawing pain in the centre of the stomach. But stomach ulcers are not always painful and some people may have other symptoms, such as indigestion, heartburn and feeling sick.If you think you may have symptoms of a stomach ulcer, stop taking naproxen and contact your doctor. You can report any suspected side effect using the Yellow Card safety scheme.