Photo by Rhoda Baer
Physicians may still prescribe a controversial drug combination despite safety concerns, according to a study published in Pharmacology Research & Perspectives.
Regulatory agencies have warned against prescribing the antiplatelet agent clopidogrel with the proton pump inhibitors (PPIs) omeprazole and esomeprazole.
A PPI may be prescribed with clopidogrel to reduce the risk of gastrointestinal bleeding associated with antiplatelet therapy.
However, concomitant use of clopidogrel and esomeprazole/omeprazole is thought by some to reduce the pharmacological activity of clopidogrel.
In 2009 and 2010, regulatory agencies in Europe and the US published statements advising against concomitant use of clopidogrel and the aforementioned PPIs.
Willemien J. Kruik-Kolloffel, PharmD, of Medisch Spectrum Twente in Enschede, The Netherlands, and his colleagues wanted to determine if this recommendation was followed in The Netherlands.
The researchers studied data spanning the period from 2008 to 2011 and encompassing 39,496 patients. Forty percent of the patients did not use gastroprotective drugs at all during the study period.
Twenty-seven percent of patients were taking gastroprotective drugs before starting clopidogrel, 23% started gastroprotective drugs and clopidogrel concomitantly, and 10% started gastroprotective drugs at least 4 weeks after starting clopidogrel.
Among the patients who started a gastroprotective drug and clopidogrel concomitantly, an average of 40% started on esomeprazole/omeprazole before the first statement from a regulatory agency was released in January 2009.
This percentage decreased to around 20% after the statements were released. The percentage of patients starting on other PPIs rose from 60% to about 80%.
After the last statement was released in February 2010, there was an 11.9% decrease in dispensation of omeprazole and esomeprazole and an increase of 16.0% for other PPIs.
Results were similar among the patients who started taking a gastroprotective drug at least 4 weeks after starting clopidogrel.
These data suggest the regulatory agencies’ advice was followed, though not fully. The researchers said this may be, in part, because physicians doubt the suggested interaction between clopidogrel and esomeprazole/omeprazole.
“Regulatory agencies should base their advice on sound scientific data to convince prescribers,” Dr Kruik-Kolloffel said. “We, the authors, doubt the interaction, as do a lot of professionals all around the world.”
