Esomeprazole is a prescription medication which is available only under the brand name Nexium. This medication belongs to a class of drugs known as proton pump inhibitors, or PPIs. When the body begins to digest food, acid is released in the stomach via a device known as a proton pump. The right amount of acid is necessary to enable food to digest properly, but too much causes heartburn. Nexium blocks the pump from releasing excess acid, thereby preventing this painful consequence. Nexium is most commonly used in the treatment of severe acid reflux, known as gastroesophageal reflux disease, or GERD. It can also be used in conjunction with other medications to treat stomach ulcers. Nexium is available in 20 and 40 milligram capsules, as well as in a solution to be administered intravenously. This medication should be taken one hour before meals for the length of time specified by your doctor...usually four to eight weeks. The most commonly reported side effects of Nexium include diarrhea, nausea, and headaches, but please ask your doctor for a complete list. Also, tell your doctor IMMEDIATELY if you experience an abnormal heartbeat, or any other significant changes. Nexium should not be taken with benzodiazepines, like Valium, and may decrease the absorption of certain other prescription medications. Ask your doctor for a full list of medications and conditions that should not be combined with Nexium. Nexium is one of the most frequently prescribed acid-reflux medications. However, this medication must always be used under the direct care of a physician. Please ask for and review all of the patient information provided by your doctor before taking Nexium.