39481
document
A randomized , controlled study on the influence of acetaminophen , diclofenac , or naproxen on aspirin-induced inhibition of platelet aggregation . Nonsteroidal anti-inflammatory drugs ( NSAID ) may interfere with aspirin ( acetylsalicylic acid ) and increase the risk for cardiovascular events . The clinical relevance is uncertain . The aim of this study was to analyse the influence of a co-administration of aspirin and NSAID on platelet aggregation . In a randomized , placebo controlled trial , eleven healthy volunteers were studied during 4 separate study periods of 4 days each . Individuals were treated on each occasion with 100 mg aspirin daily in combination with either 3 x 1 g acetaminophen , 3 x 50 mg diclofenac , 3 x 250 mg naproxen , or 3 x 1 placebo . Primary hemostasis was assessed with a platelet function analyser ( PFA-100 ) , which measures the closure time ( CT ) of a collagen- and epinephrine-coated pore by aggregating platelets in flowing blood . Naproxen enhanced the anti-aggregatory action of aspirin after 24 h ( CT rising from 104+/-16 s at baseline to 212+/-69 s at 24 h , P < 0.001 ) , which was not seen with any other drug combination . Diclofenac reduced the anti-aggregatory action of aspirin in the first two days , since the CT did not rise significantly ( 109+/-19 s , 148+/-56 s , and 168+/-66 s at 0 h , 24 h , 48 h , respectively , P > 0.05 ) . Acetaminophen had no effect compared with placebo . After 4 days of treatment platelet aggregation was similarly inhibited by all combinations . We conclude that a co-administration of NSAID and aspirin may interfere with platelet inhibition at the beginning of a treatment with an increase of naproxen and a decrease of diclofenac . This effect is lost after 4 days , suggesting that a regular daily co-administration of NSAID does not have an influence on platelet inhibition by aspirin .
39482
Intervention_Pharmacological
acetaminophen
39483
Intervention_Pharmacological
diclofenac
39484
Intervention_Pharmacological
naproxen
39485
Intervention_Pharmacological
Nonsteroidal anti-inflammatory drugs ( NSAID )
39486
Intervention_Pharmacological
aspirin ( acetylsalicylic acid )
39487
Intervention_Pharmacological
aspirin
39488
Intervention_Pharmacological
NSAID
39489
Intervention_Pharmacological
aspirin
39490
Intervention_Pharmacological
3 x 1 g acetaminophen , 3 x 50 mg diclofenac , 3 x 250 mg naproxen
39491
Intervention_Control
placebo
39492
Intervention_Pharmacological
Naproxen
39493
Intervention_Pharmacological
aspirin
39494
Intervention_Pharmacological
Diclofenac
39495
Intervention_Pharmacological
aspirin
39496
Intervention_Pharmacological
Acetaminophen
39497
Intervention_Control
placebo
39498
Intervention_Pharmacological
NSAID
39499
Intervention_Pharmacological
aspirin
39500
Intervention_Pharmacological
naproxen
39501
Intervention_Pharmacological
diclofenac
39502
Intervention_Pharmacological
NSAID
39503
Intervention_Pharmacological
aspirin
39504
Outcome_Physical
platelet aggregation
39505
Outcome_Physical
cardiovascular events
39506
Outcome_Physical
platelet aggregation
39507
Outcome_Physical
Primary hemostasis
39508
Outcome_Other
the
39509
Outcome_Physical
closure time ( CT )
39510
Outcome_Other
of a collagen- and epinephrine-coated pore by aggregating platelets in flowing blood
39511
Outcome_Physical
anti-aggregatory action
39512
Outcome_Physical
CT
39513
Outcome_Physical
anti-aggregatory action
39514
Outcome_Physical
CT
39515
Outcome_Physical
platelet aggregation
39516
Outcome_Physical
platelet inhibition
39517
Outcome_Physical
platelet inhibition
39518
Participant_Condition
eleven healthy volunteers