Go Ad-Free
logoThe People's Perspective on Medicine



Prevacid, like Prilosec, fights acid secretion by blocking the final step. This so-called proton pump is prescribed for the short-term treatment of duodenal ulcer, inflammation of the esophagus due to acid splashback, and for rare conditions of abnormal acidity such as Zollinger-Ellison syndrome.

It is a delayed-release capsule that is extremely effective in reducing stomach acid. Prevacid should not be prescribed as maintenance therapy to keep ulcers from coming back.

Side Effects and Interactions

Prevacid is well tolerated and side effects are uncommon. Diarrhea, stomach ache, and nausea have been reported.

Less common were muscle weakness, rash, chest pain, constipation, gallstones, changes in blood sugar, and elevated liver enzymes. Report any symptoms or suspected reactions to your physician promptly.

Prevacid interacts with very few drugs, but some other prescription medications require acidity for absorption. Prevacid can interfere with such medicines, which include Nizoral, ampicillin, iron supplements, and Lanoxin, among others.

Vitamin B12 also requires an acid environment for absorption, and long-term use of Prevacid could result in low B12 reserves. This may have consequences for the nerves and blood. Please discuss this with your doctor.

The asthma drug theophylline also may be affected by Prevacid.

People taking acid-suppressing drugs such as Prevacid should not take enteric-coated peppermint oil. The enteric coating is designed to keep the oil from being absorbed until it reaches the more alkaline lower intestine. But when there is very little stomach acid, the enteric coating may dissolve prematurely, releasing the oil into the stomach.

Be sure to check with your pharmacist and physician about potential interactions before taking any other medication or herb in combination with Prevacid.

Special Precautions

Animal studies have shown that Prevacid is associated with a dose-related increase in stomach cancers. It is not known whether this risk also applies to humans.

In addition, because it is so effective at reducing stomach acid concentrations, patients taking this medicine have higher levels of certain microorganisms in their stomachs than would normally survive there. Scientists do not yet know whether these bacteria have negative long-term consequences.

Regular supplementation with vitamins C and E might in theory provide protection against nitrosamines produced by the bacteria.

Taking the Medicine

Prevacid should be taken before meals. These delayed-release capsules should not be opened, crushed or chewed.

If Carafate is needed, it should be taken at least 30 minutes before Prevacid.

Rate this article
4- 5 ratings
About the Author
Joe Graedon is a pharmacologist who has dedicated his career to making drug information understandable to consumers. His best-selling book, The People’s Pharmacy, was published in 1976 and led to a syndicated newspaper column, syndicated public radio show and web site. In 2006, Long Island University awarded him an honorary doctorate as “one of the country's leading drug experts for the consumer.”.
Tired of the ads on our website?

Now you can browse our website completely ad-free for just $5 / month. Stay up to date on breaking health news and support our work without the distraction of advertisements.

Browse our website ad-free
Join over 150,000 Subscribers at The People's Pharmacy

We're empowering you to make wise decisions about your own health, by providing you with essential health information about both medical and alternative treatment options.