Prilosec, a brand name for the drug omeprazole, is available both over the counter and in a higher-strength prescription form. Prilosec is used to treat disorders involving stomach acid, including gastroesophageal reflux disease, known as GERD, and frequent heartburn. Although you can take Prilosec with most types of magnesium, it can cause problems with one type of magnesium medication.
Prilosec is a proton-pump inhibitor that decreases production of stomach acid. The over-the-counter medicine is indicated if you experience heartburn two or more days a week. The prescription-strength version is indicated if you have been diagnosed with GERD, in which acid reflux may be severe enough to damage the esophagus. Prescription-strength Prilosec also is useful for treating gastrointestinal ulcers and disorders involving excessive production of stomach acid.
Different magnesium formulations have varying uses. Magnesium supplements provide sufficient amounts of this essential mineral if you don't get enough from food. Some types of magnesium, such as magnesium oxide, work as an antacid or as a laxative. Another form of magnesium, magnesium salicylate, is a nonsteroidal anti-inflammatory drug. Like another salicylate, aspirin, magnesium salicylate reduces chemicals in the body that cause pain and inflammation. It seems to be more effective than aspirin for reducing pain, swelling and joint stiffness caused by arthritis. This is the type of magnesium that may have interactions with Prilosec.
Prilosec and Salicylate Interaction
Taking a salicylate medication when you're also taking a proton-pump inhibitor such as Prilosec may decrease the bioavailability of the salicylate and thus decrease its effectiveness, according to Drugs.com. Limited research found that taking omeprazole for two days before taking aspirin led to reduced blood levels of the aspirin. It's possible that suppression of stomach acid production may reduce aspirin absorption from the digestive tract. Some research results are conflicting, however.
Prilosec and Enteric-Coated Salicylates
In another study cited by Drugs.com, participants taking aspirin after taking omeprazole for four days did not experience reduced bioavailability of the salicylate. However, those taking aspirin that had an enteric coating experienced a significantly increased absorption rate of the salicylate, apparently because the change in stomach acid levels to a more alkaline state caused premature breakdown of the coating. This action might increase the risk of certain side effects connected with salicylates, such as gastrointestinal bleeding and ulcers.