Alert FDA

Już była kiedyś o tym mowa, ale sprawa jest dosyć istotna, a interakcja często możliwa:

SILVER SPRING, Md -- November 17, 2009 -- The US Food and Drug Administration (FDA) has new data showing that the proton pump inhibitor (PPI) omeprazole (Prilosec/Prilosec OTC) reduces the anti-blood clotting effect of clopidogrel (Plavix) by almost half when these 2 medicines are taken by the same patient. Patients at risk for heart attacks or strokes who use clopidogrel to prevent blood clots will not get the full effect of this medicine if they are also taking omeprazole; therefore, the FDA recommends that the coadministration of omeprazole and clopidogrel be avoided.

The new recommendations, updated from a January 2009 Early Communication, are based on study results from the manufacturers of clopidogrel. The studies confirm that coadministration of omeprazole with clopidogrel results in decreased levels of clopidogrel's active metabolite, reducing clopidogrel's anticlotting effect.

Omeprazole inhibits the drug-metabolising enzyme (CYP2C19), which is responsible for the conversion of clopidogrel into its active metabolite. The new studies compared the amount of clopidogrel's active metabolite in the blood and its effect on platelets in patients who took clopidogrel plus omeprazole versus those who took clopidogrel alone. A reduction in active metabolite levels of about 45% was found in those who received clopidogrel with omeprazole compared with those taking clopidogrel alone. The effect of clopidogrel on platelets was reduced by as much as 47% in patients receiving clopidogrel and omeprazole together. These reducti