In May 2009, the European Medicines Agency (EMA) raised concern about a possible risk of interaction between proton pump inhibitors (PPI) and clopidogrel-containing medicines.
Last year’s warning came in response to a number of studies which suggested that the concomitant use of PPIs and clopidogrel might reduce the effectiveness of clopidogrel, which could increase the risk of blood clots such as heart attacks and strokes.
Clopidogrel is used to treat patients who have had blood clots such as heart attacks or strokes. Plavix® is one of the clopidogrel-containing products that are on the Danish market. Clopidogrel is converted in the liver from an inactive form to an active form, which prevents the platelets from clumping together.
PPIs reduce the release of acid in the stomach and are used to treat excess stomach acid in connection with e.g. heartburn and stomach ulcers. As clopidogrel increases the risk of stomach ulcers, PPIs are often given to patients receiving clopidogrel. PPIs include a number of products that contain omeprazole, esomeprazole, lansoprazole, pantoprazole and rabeprazole.
The EMA’s Committee for Medicinal Products for Human Use (CHMP) has now analysed data from a line of new studies. Against this background, the CHMP restates it warning against using clopidogrel at the same time as two of the PPIs: omeprazole and esomeprazole. Studies show that there is an interaction between clopidogrel and omeprazole/esomeprazole. The interaction probably occurs because the conversion of clopidogrel into its active form is inhibited by omeprazole or esomeprazole treatment.
However, based on the currently available data, the CHMP has also concluded that there are no grounds to extend the warning to other PPIs
In consequence, the CHMP has replaced the present class warning for all PPIs with a warning stating that only the concomitant use of clopidogrel and omeprazole or esomeprazole should be avoided.
The Danish Medicines Agency advises patients who are treated with clopidogrel and omeprazole/esomeprazole to continue their treatment, but to discuss future treatment with their doctor, including the possibility of using an alternative PPI.
Patients who are treated with clopidogrel and PPIs other than omeprazole and esomeprazole can safely continue treatment.
For further information, please contact Chief Medical Officer Jens Heisterberg, tel. +45 4488 9350.
Danish Medicines Agency, 22 March 2010