Background and Goal of Study: Nonsteroidal anti-inflammatory agents (NSAIDs) have an antiaggregant effect by inhibiting steps in thromboxane A2 (TxA2)-mediated platelet activation (1). Until now, this effect has not been fully assessed compared with aspirin (ASA). The objective of this study is to determine if the administration of an oral standard dose of ibuprofen (600 mg) is able to produce an antiaggregant effect similar tan the one produced by ASA (100-300 mg, therapeutic range).

Materials and Methods: IBU-Agree is a descriptive study, made in healthy subjects taking a 600 mg tablet of ibuprofen because of moderate headache. They had no any haemostasis complication history (Rapaport classical questions (2) were included also to support it). Subjects taking any NSAID or garlic tablets less than 3 days before were not included. A sample of 3 ml of whole blood was obtained through venous puncture before 180´ after the intake (ibuprofen Tmax: 90'-150'). To assess the antiaggregation power of ibuprofen, we used the specific ASA kit for the device VerifyNow® (Accumetrics, Inc., San Diego, CA-USA). The results are shown in ARU (Aspirin Reactive Units): >550 ARU means a normal platelet reactivity without dysfunction related with ASA or similar drugs; < 550 ARU means antiaggregation related with the mechanism of action of ASA. As it is a descriptive study, no statistics is needed.

Results and Discussion: 14 healthy subjects were included (10 M, 4 F). Age range was 22-54 y and body weight range was 43-89 kg. The samples were obtained between 100' and 165' after the intake of ibuprofen. The results showed that 13/14 subjects were antiaggregated at that time (ARU range 350-490) and 1/14 subject was no antiaggregated (ARU 591).

Conclusion(s): The results of this study show that the intake of 600 mg of ibuprofen induces an antiaggregated state similar to the one after the therapeutic administration of ASA (100-300 mg). Although more studies are needed to confirm if this antiaggregated state could be related with a haemorrhage tendency, we could anticipate that patients with haemostatic disturbances or fragile ones should avoid the intake of NSAIDs, mainly in the perioperative period.

References:
(1) Armstrong AW, Golan DE. Pharmacology of hemostasis and thrombosis. LWW, 2008, Baltimore-PA.
(2) Rapaport SI. Preoperative hemostatic evaluation: which test if any?. Blood 1983;61:229-31.

Assessment of the antiaggregant effect of ibuprofen in healthy subjects: IBU-Agree study