Morphine is recommended in patients with ST-segment-elevation myocardial infarction, including those undergoing primary percutaneous coronary intervention ( PCI ). Suboptimal antiplatelet effect during and after primary percutaneous coronary intervention is associated with increased thrombotic complications.
It was hypothesized a potential drug-drug interaction between Morphine and antiplatelet agents.
Researchers have assessed platelet inhibition after a loading dose of the currently recommended antiplatelet agents in ST-segment-elevation myocardial infarction patients according to Morphine use.
Three hundred patients undergoing primary percutaneous coronary intervention receiving either Prasugrel [ Efient ] ( n = 95 ) or Ticagrelor [ Brilique ] ( n = 205 ) loading dose had platelet reactivity assessed by VerifyNow 1, 2, and 4 hours after loading dose.
Patients treated with Morphine ( n = 95; 32% ) had a higher incidence of vomit ( 15% versus 2%; P = 0.001 ).
P2Y12 reactivity units 2 hours after the loading dose was 187 ( 153-221 ) and 133 ( 102-165 ) in patient with and without Morphine ( P less than 0.001 ); the difference persisted after excluding patients with vomit ( P less than 0.0001 ).
High residual platelet reactivity ( P2Y12 reactivity units greater than or equal to 208 ) at 2 hours was found in 53% and 29% patients with and without Morphine ( P less than 0.001 ) and without difference between Prasugrel and Ticagrelor patients.
The independent predictors of high residual platelet reactivity at 2 hours were morphine use ( odds ratio, OR=2.91 [ 1.71-4.97 ]; P less than 0.0001 ) and age ( OR=1.03 [1.01-1.05]; P = 0.010 ).
Morphine remained associated with high residual platelet reactivity after propensity score adjustment ( c-statistic, 0.68; 95% confidence interval, 0.66-0.70; P = 0.879 for Hosmer-Lemeshow test ).
In patients with ST-segment-elevation myocardial infarction ( STEMI ), Morphine use is associated with a delayed onset of action of the oral antiplatelet agents.
This association persisted after adjusting for the propensity to receive Morphine and after excluding patients with vomit. ( Xagena )
Parodi G et al, Circ Cardiovasc Interv 2014;8(1)