Multiplate^® tests: Sensitivity towards anti-platelet agents:

The sensitivity of Multiplate^® analysis towards the action of anti-platelet agents can be varied depending on the Multiplate^® test applied. GpIIb/IIIa antagonists block the signal reaction of Multiplate^® analysis and therefore every test performed. Cyklooxygenase inhibition by Aspirin^® or other drugs blocks aggregation in ASPItest and COLtests, but not platelet function triggered by the ADP receptor (in ADPtest and ADPtest HS) or the thrombin receptor (TRAPtest). Clopidogrel and other ADP receptor antagonists inhibit ADPtest and ADPtest HS, but not TRAPtest, COLtest and ASPItest.

The detection of the action of Clopidogrel may be disturbed by an in vitro depletion in ionized calcium of the sample (i.e. by the analysis of citrated blood) . It is therefore recommended to use samples with physiologic calcium levels for Multiplate^® analysis, i.e. heparin blood or hirudin blood.