title: Valdecoxib does not impair platelet function.
abstract: The platelet effects of a supratherapeutic dose of the new cyclooxygenase (COX)-2 specific inhibitor, valdecoxib (40 mg twice a day), naproxen 500 mg twice a day, diclofenac 75 mg twice a day, and placebo were compared in 62 healthy adult subjects in this 7(1/2) day single-center, randomized, placebo-controlled trial. Platelet aggregation responses (to arachidonate [AA], collagen, and adenosine diphosphate [ADP]), bleeding time, and serum thromboxane B(2) (TxB(2)) concentrations were measured at baseline and at regular intervals on days 1 and 8. Valdecoxib had no effect on platelet function. Naproxen and diclofenac significantly reduced the platelet aggregation response to AA and to a lesser extent collagen and ADP at most assessments compared with placebo. Naproxen significantly lowered serum TxB(2) levels. In contrast to standard doses of 2 nonsteroidal antiinflammatory drugs (NSAIDs), a supratherapeutic valdecoxib dosage does not impair platelet function (COX-1). Valdecoxib may be a safer analgesic option than conventional NSAIDs in patients for whom bleeding complications are a concern. (Am J Emerg Med 2002;20:275-281.
authors.affiliation: Quintiles Phase I Services, 11250 Corporate Ave, Lenexa, KS, USA.
authors.forename: Philip T
authors.initials: PT
authors.lastname: Leese
authors.forename: Sheela
authors.initials: S
authors.lastname: Talwalker
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Kent
authors.forename: David P
authors.initials: DP
authors.lastname: Recker
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D001760:Bleeding Time; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D004008:Diclofenac / Q000494:pharmacology; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007555:Isoxazoles / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D009288:Naproxen / Q000494:pharmacology; D010974:Platelet Aggregation / Q000187:drug effects*; D018709:Statistics, Nonparametric; D013449:Sulfonamides / Q000494:pharmacology*; D013929:Thromboxane B2 / Q000097:blood; D000096926:Benzenesulfonamides
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D016861:Cyclooxygenase Inhibitors; D004008:Diclofenac; D007555:Isoxazoles; D009288:Naproxen; D013449:Sulfonamides; D013929:Thromboxane B2; C406224:valdecoxib; D000096926:Benzenesulfonamides