Plavix, PPI Combo: Risky for Heart Patients?
Study Shows Risks of Combining Plavix and Proton Pump Inhibitors
By
Salynn Boyles
WebMD Health News
Reviewed By
Elizabeth Klodas, MD, FACC
March 3, 2009 -- Heart attack patients who take an acid-reducing proton pump inhibitor (PPI) drug like Prilosec or Nexium in combination with the
antiplatelet drug Plavix are more likely to have a second heart attack than patients who don't take PPIs, according to new research.
The findings confirm several smaller trials and one larger one, reported
just weeks ago, suggesting that PPIs can inhibit the blood clot-inhibiting
activity of Plavix, also known as clopidogrel.
Heart patients in the study who took Plavix with a PPI had a 25% increased
risk of dying or of requiring hospitalization for heart-related issues,
compared to patients who took Plavix alone, says study researcher P. Michael
Ho, MD, PhD of the Denver VA Medical Center. Even after adjusting for factors
such as patient age and other health factors, the concomitant use of Plavix and
a PPI was still associated with a substantially higher risk of subsequent heart
attacks or need for revascularization procedures.
The study appears in the March 4 issue of The Journal of the American
Medical Association.
"It is increasingly clear that PPIs should not be prescribed to patients
taking clopidogrel unless there is a good indication for doing so," Ho
tells WebMD.
PPIs Routinely Given With Plavix
Along with aspirin, Plavix is routinely
prescribed after a heart attack or as part of treatment for heart conditions
like unstable angina to prevent potentially
life-threatening blood clots from forming.
PPIs, such as Prilosec, Nexium, Prevacid, Aciphex, and Protonix, are often prescribed
as well to reduce the risk of gastric bleeding from the blood-thinning
combination treatment.
But several recent studies suggest that patients who take Plavix and PPIs
together have an increased risk for recurrent heart attacks and death from
other heart-related causes.
In an effort to shed light on the issue, Ho and colleagues followed more
than 8,000 patients treated for heart attacks or unstable angina at 127
Veterans Administration hospitals across the country.
Plavix was prescribed to all the patients, and 64% were prescribed a
PPI.
Over three years of follow-up, about 30% of the patients who took Plavix
plus a PPI either died or were hospitalized for heart-related causes, compared
to 21% of the patients who took the antiplatelet drug without a PPI.
Taking Plavix with a PPI at any time during the follow-up was associated
with a 25% increase in risk for death or hospitalization.
American Heart Association president Timothy Gardner, MD, tells WebMD that
it is now clear that PPIs should be prescribed cautiously to heart patients
taking Plavix.
"If a patient has a history of GI bleeding, we know that [Plavix] can
increase the risk of recurrence," he says. "It may be that we need to
limit the use of PPIs to these patients and other patients who have a clear
need for protection."
Are All PPIs Equal?
Findings from a large Canadian trial, reported in late January, suggest that
all PPIs are not equal when it comes to inhibiting the antiplatelet activity of
Plavix.
The study included more than 13,000 heart attack patients treated with
Plavix with or without a PPI.
Study researcher David N. Juurlink, MD, PhD, tells WebMD that although most
PPIs did appear to interact with Plavix, one -- Protonix (pantoprazole, Wyeth
Pharmaceuticals) -- showed no evidence of reducing the effectiveness of the
antiplatelet drug.
Juurlink says he received no funding from Wyeth or any other drug company to
conduct his research.
"Literally millions of people who are taking Plavix and aspirin are also
taking a PPI," he says. "If a patient on Plavix requires a PPI, it
would seem to make sense to preferentially give them pantoprazole."
In late January, the FDA announced that Plavix manufacturers Bristol-Myers
Squibb and Sanofi-Aventis had agreed to conduct studies to clarify the impact
of PPIs and other drugs on the effectiveness of Plavix in heart patients.
"Patients taking clopidogrel should consult with their healthcare
provider if they are currently taking or considering taking a PPI, including
Prilosec OTC," the statement noted.
Wyeth Pharmaceutical spokeswoman Gwen Fisher tells WebMD that the company is
awaiting the results from these trials.
A spokesman for AstraZeneca, which makes Prilosec and Nexium, tells WebMD
that rigorously designed, prospective studies are needed to determine if PPIs
interact with Plavix.
"To date, there have been contradictory conclusions and scientific
limitations in studies about the potential interaction between clopidogrel and
PPIs," AstraZeneca spokesman Blair Hains says. "AstraZeneca believes
that before definitive conclusions are drawn, more evidence involving thorough,
well-designed, prospective clinical trials is needed."
Calls to Plavix manufacturer Bristol Myers Squibb were not returned by
publishing time.
SOURCES: Ho, M.P. The Journal of the American Medical Association, March 4,
2009; vol 301: pp 937-944. P. Michael Ho., MD, PhD, assistant professor, University of Colorado at
Denver. David Juurlink, BPhm, MD, PhD, head, division of clinical pharmacology and
toxicology, Sunnybrook Health Sciences Center, Toronto. Timothy J. Gardner, MD, president, American Heart Association. FDA statement on safety review of Plavix, Jan. 26, 2009. Gwen Fisher, public relations, Wyeth Pharmaceuticals. Juurlink, D.N. CMAJ Online, Jan. 28, 2009.
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