Objective. To investigate whether low-dose naproxen sodium (220 mg twice a day) interferes with aspirin's antiplatelet effect in healthy subjects. Methods. We performed a crossover, open-label study in 9 healthy volunteers. They received for 6 days 3 different treatments separated by 14 days of washout: 1) naproxen 2 hours before aspirin, 2) aspirin 2 hours before naproxen, and 3) aspirin alone. The primary end point was the assessment of serum thromboxane B2 (TXB2) 24 hours after the administration of naproxen 2 hours before aspirin on day 6 of treatment. In 5 volunteers, the rate of recovery of TXB2 generation (up to 72 hours after drug discontinuation) was assessed in serum and in platelet-rich plasma stimulated with arachidonic acid (AA) or collagen. Results. Twenty-four hours after the last dosing on day 6 in volunteers receiving aspirin alone or aspirin before naproxen, serum TXB2 was almost completely inhibited (median [range] 99.1% [97.4-99.4%] and 99.1% [98.0-99.7%], respectively). Naproxen given before aspirin caused a slightly lower inhibition of serum TXB2 (median [range] 98.0% [90.6-99.4%]) than aspirin alone (P = 0.0007) or aspirin before naproxen (P = 0.0045). All treatments produced a maximal inhibition of AA-induced platelet aggregation. At 24 hours, compared with baseline, collagen-induced platelet aggregation was still inhibited by aspirin alone (P = 0.0003), but not by aspirin given 2 hours before or after naproxen. Compared with administration of aspirin alone, the sequential administration of naproxen and aspirin caused a significant parallel upward shift of the regression lines describing the recovery of platelet TXB2. Conclusion. Sequential administration of 220 mg naproxen twice a day and low-dose aspirin interferes with the irreversible inhibition of platelet cyclooxygenase 1 afforded by aspirin. The interaction was smaller when giving naproxen 2 hours after aspirin. The clinical consequences of these 2 schedules of administration of aspirin with naproxen remain to be studied in randomized clinical trials.

Low-dose naproxen interferes with the antiplatelet effects of aspirin in healthy subjects: recommendations to minimize the functional consequences

ANZELLOTTI, PAOLA;CAPONE, Marta Luciana;TACCONELLI, Stefania;BRUNO, ANNALISA;DI FRANCESCO, LUIGIA;RENDA, GIULIA;PATRIGNANI, Paola
2011-01-01

Abstract

Objective. To investigate whether low-dose naproxen sodium (220 mg twice a day) interferes with aspirin's antiplatelet effect in healthy subjects. Methods. We performed a crossover, open-label study in 9 healthy volunteers. They received for 6 days 3 different treatments separated by 14 days of washout: 1) naproxen 2 hours before aspirin, 2) aspirin 2 hours before naproxen, and 3) aspirin alone. The primary end point was the assessment of serum thromboxane B2 (TXB2) 24 hours after the administration of naproxen 2 hours before aspirin on day 6 of treatment. In 5 volunteers, the rate of recovery of TXB2 generation (up to 72 hours after drug discontinuation) was assessed in serum and in platelet-rich plasma stimulated with arachidonic acid (AA) or collagen. Results. Twenty-four hours after the last dosing on day 6 in volunteers receiving aspirin alone or aspirin before naproxen, serum TXB2 was almost completely inhibited (median [range] 99.1% [97.4-99.4%] and 99.1% [98.0-99.7%], respectively). Naproxen given before aspirin caused a slightly lower inhibition of serum TXB2 (median [range] 98.0% [90.6-99.4%]) than aspirin alone (P = 0.0007) or aspirin before naproxen (P = 0.0045). All treatments produced a maximal inhibition of AA-induced platelet aggregation. At 24 hours, compared with baseline, collagen-induced platelet aggregation was still inhibited by aspirin alone (P = 0.0003), but not by aspirin given 2 hours before or after naproxen. Compared with administration of aspirin alone, the sequential administration of naproxen and aspirin caused a significant parallel upward shift of the regression lines describing the recovery of platelet TXB2. Conclusion. Sequential administration of 220 mg naproxen twice a day and low-dose aspirin interferes with the irreversible inhibition of platelet cyclooxygenase 1 afforded by aspirin. The interaction was smaller when giving naproxen 2 hours after aspirin. The clinical consequences of these 2 schedules of administration of aspirin with naproxen remain to be studied in randomized clinical trials.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11564/178034
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 59
  • ???jsp.display-item.citation.isi??? 45
social impact