I have taken Prilosec (20mg twice a day) since 1995. I am also trying to treat an abscess in a tooth, unsuccessfully. I have taken a week's course of antibiotics several times, but the infection continues. I am worried about losing a section of the jaw. My question: Does Prilosec interfere with the stomach's absorption of antibiotics?

Dennis

Your question about the possible effects of Prilosec on absorption of drugs is very interesting. Prilosec (omeprazole) is a proton-pump inhibitor (PPI), one of a class of powerful drugs that block the production of stomach acid. PPIs are used to treat acid-related disorders such as GERD (gastroesophageal reflux disease), esophagitis and ulcers of the stomach and upper intestine (duodenum). The most common side effects -- diarrhea, headache and abdominal bloating -- occur only in small numbers of patients and rarely require discontinuing the medication.

Stomach acid is an important part of the normal digestive process. Enzymes produced by the stomach, which help to break down proteins, require high acid levels to function optimally. Acid in the stomach also acts to kill many potentially harmful germs in our food.

So, in theory, a lack of stomach acid might lead to poor digestion and absorption of nutrients and medications. However, in reality, using drugs to lower levels of stomach acid usually does not cause significant digestive problems. While many people take PPIs continuously as you do, reports of malabsorption among such patients have been extremely rare. This is probably because the PPIs do not block acid 24 hours a day, and enough acid is produced to effectively carry out the body's digestive needs.

To answer your specific question, there is a theoretical potential for PPIs to interfere with the absorption of certain antibiotics that require stomach acid for their normal absorption (for example, ketoconazole and ampicillin). However, these types of interactions have not been commonly described in the medical literature. In fact, most antibiotics do not depend on stomach acid for their absorption and would not be adversely affected by PPI therapy. A more likely explanation for your failure to respond to multiple courses of antibiotics for the tooth abscess is that the antibiotics are not penetrating far enough into the abscess cavity. In many cases, the only effective way to treat such infections is to drain the abscess. In your case this may require specialized work by a dentist or oral surgeon. You should discuss your problem with one of these specialists if you have not already done so.