Drug Interactions

Prilosec OTC® in Combination with Other Drugs 

Prilosec OTC®, Plavix®, and Pletal® (clopidogrel and cilostazol): FDA Health Advisory Issued

A public health advisory was issued by the FDA on November 17, 2009 regarding clopidogrel, (marketed as PlavixR) recommending patients avoid the combination of omeprazole with this drug. Subsequently in March, 2010, a potential for interaction was found with cilostazol (marketed as PletalR). Therefore, P&G added this warning to Prilosec OTC’s label as well.

The FDA recommends patients avoid the combination of these drugs because, according to data provided by the makers of Plavix® and Pletal®, omeprazole may reduce the anti-clotting effect of Plavix® and Pletal®. However, the FDA recognizes that when used individually, these products provide significant health benefits.

In 2012, FDA issued a Drug Safety Communication regarding an increased incidence of Clostridium difficile-associated diarrhea with use of proton pump inhibitors (PPI’s). Based on this information, P&G added a diarrhea warning to Prilosec OTC’s labeling indicating that consumers should stop taking the drug and contact their physician.

In 2014, FDA recommended all proton pump inhibitors labeling contain wording to warn consumers that they should seek the advice of a doctor or pharmacist if they are considering taking an OTC PPI while also taking methotrexate or mycophenolate mofetil due to potential drug-drug interactions. Co-administration can lead to methotrexate toxicity or a decrease in effectiveness of mycophenolate mofetil.

When used as directed, Prilosec OTC has a strong safety profile—millions of consumers have tried it since it became available over-the-counter in 2003. However, consistent with the FDA, we encourage our consumers to avoid the combination of omeprazole with the drugs mentioned above unless under the care of their physician.

Individuals should talk to a medical professional before they stop or start taking any medication or if they have additional questions.

Please refer to the FDA drug safety site for more information:

Plavix (Clopidogrel)

Pletal (Cilostazol)

Clostridium difficile-associated diarrhea


Plavix is a registered trademark of Sanofi.
Pletal is a registered trademark of Otsuka Pharmaceutical Co.