News Report on Concommitant Use of Ibuprofen and Asprin

[Guest guest]

The following came through the news today. For those that do not understand

medical jargon, concomitant means taking at the same time, and myocardial

infarction = heart attack.

Some of the highlighting in bold letters is my emphasis on the story.

http://www.fda.gov/cder/drug/InfoSheets/HCP/ibuprofen_aspirinHCP.htm

New Information for Healthcare Professionals

Concomitant Use of Ibuprofen and Aspirin

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New Information [9/2006] - Concomitant Use of Ibuprofen and Aspirin:

Ibuprofen can interfere with the anti-platelet effect of low dose aspirin (81 mg

per day), potentially rendering aspirin less effective when used for

cardioprotection and stroke prevention. Healthcare professionals should advise

consumers and patients regarding the appropriate concomitant use of ibuprofen

and aspirin.

This information reflects FDA’s current analysis of data available to FDA

concerning these drugs. FDA intends to update this sheet when additional

information or analyses become available.

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To report serious adverse events associated with the use of these drugs, please

contact the FDA MedWatch program using the contact information at the bottom of

this sheet.

Considerations

Health care professionals should consider:

a.. Counseling patients about the appropriate timing of ibuprofen dosing if

they are also taking aspirin for cardioprotective effects.

b.. With occasional use of ibuprofen, there is likely to be minimal risk from

any attenuation of the antiplatelet effect of low dose aspirin, because of the

long-lasting effect of aspirin on platelets.

c.. Patients who use immediate release aspirin (not enteric coated) and take a

single dose of ibuprofen 400 mg should dose the ibuprofen at least 30 minutes or

longer after aspirin ingestion, or more than 8 hours before aspirin ingestion to

avoid attenuation of aspirin’s effect.

d.. Recommendations about the timing of concomitant use of ibuprofen and

enteric-coated low dose aspirin cannot be made based upon available data.

e.. Other nonselective OTC NSAIDs should be viewed as having the potential to

interfere with the antiplatelet effect of low-dose aspirin unless proven

otherwise.

f.. Prescribing analgesics that do not interfere with the antiplatelet effect

of low dose aspirin for high risk populations.

Data Summary

Aspirin is available over-the-counter as a tablet, buffered tablet, effervescent

tablet, or caplet in immediate-release formulations and as a tablet in

enteric-coated formulations. Individual aspirin doses range from 81 mg to 500

mg.

It has been demonstrated in published and unpublished human ex vivo studies,

that ibuprofen interferes with the antiplatelet activity of low dose aspirin (81

mg, immediate release) when they are ingested concurrently. The mechanism by

which this occurs may be through competitive inhibition of the acetylation site

of cyclooxygenase (COX) in the platelet. Both ibuprofen (reversible inhibition)

and aspirin (irreversible inhibition) occupy nearby sites on COX, such that the

presence of ibuprofen interferes with aspirin binding. Once the ibuprofen

releases from the binding site, COX will not be inhibited because some aspirin

available to bind will have been excreted. This ibuprofen interference

attenuates the expected aspirin-mediated irreversible inhibition of thromboxane

B2 (TXB2) production and the expected inhibition of platelet aggregation.

There are no clinical endpoint studies conducted specifically to evaluate the

interaction. Attenuation of 90% or more of the antiplatelet effect of aspirin

has been defined as clinically significant by some investigators. Unpublished

single dose trials with ibuprofen 400 mg indicate that interference with

aspirin’s antiplatelet activity, as measured by TXB2 levels and platelet

activation studies, occurs when ibuprofen is taken within 30 minutes after

immediate release aspirin dosing. The interaction also occurs when a single dose

of ibuprofen 400 mg is taken 8 hours or less prior to aspirin dosing. At least 8

hours should elapse after ibuprofen dosing, before giving aspirin, to avoid

significant interference.

One study showed that the antiplatelet effect of enteric-coated low dose aspirin

is attenuated when ibuprofen 400 mg is dosed 2, 7, and 12 hours after aspirin.6

FDA is unaware of studies that have looked at the same type of interference by

ketoprofen with low dose aspirin, and there are no data looking at

nonprescription doses of naproxen. There is at least one study that has

suggested that naproxen at higher than nonprescription doses may interfere with

aspirin’s anti-platelet activity when they are co-administered. Acetaminophen

appears to not interfere with the antiplatelet effect of low dose aspirin, and

FDA is unaware of any interference by narcotic analgesics.

Implications

The clinical implication of the interference by ibuprofen on the anti-platelet

effect of aspirin is unclear. However, it is potentially important because the

cardioprotective effect of aspirin, when used for secondary prevention of

myocardial infarction, could be decreased or negated.

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Report serious adverse events to

FDA’s MedWatch reporting system by completing a form on line at

http://www.fda.gov/medwatch/report.htm, by faxing (1-800-FDA-0178),

by mail using the postage-paid address form provided online

(5600 Fishers Lane, Rockville, MD 20852-9787),

or by telephone (1-800-FDA-1088).

Questions? Call Drug Information, 1-888-INFO-FDA (automated) or 301-827-4570

Druginfo@...

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Date created: September 8, 2006