Interaction between the LMWH reviparin and aspirin in healthy volunteers

Aims To investigate potential interactions between reviparin and acetylsali cylic acid (ASA 300 mg o.d. from day 1-5). Methods In an open, randomized, three-way-cross over study nine healthy vol unteers received reviparin (s.c. injection of 6300 anti-Xa units) or placeb o from days 3 to 5 and acetylsalicylic acid (ASA 300 mg) or placebo from da ys 1 to 5. Assessments included bleeding time (BT), collagen (1 mu g ml(-1) ) induced platelet aggregation (CAG), heptest, plasma antifactor Xa-activit y and activated partial thromboplastin time (aPTT). Results Median bleeding time at day 5 was 5.5 min after reverparin alone an d after ASA alone and was 9.6 min after the combination of reviparin and AS A. ASA treatment reduced CAG from 84% to 40 to 50% of A(max); values after combined treatment of reviparin with ASA were not different from those afte r ASA alone. aPTT was prolonged to 32 s after reviparin; this effect was no t modified if subjects received ASA. Combined treatment with ASA and revipa rin had no effect on plasma anti-Xa-activity and heptest compared with revi parin alone. Conclusions We could not entirely exclude a small interaction between revip arin and ASA on bleeding time, but the effect is probably without clinical significance.