Morphine associated with delayed antiplatelet activity in patients with STEMI

Use of morphine delayed the onset of action of antiplatelet agents in patients with STEMI who were undergoing PCI, researchers reported.

The study included 300 patients undergoing PCI who were receiving loading doses of prasugrel (n=95; Effient, Eli Lilly/Daiichi Sankyo) or ticagrelor (n=205; Brilinta, AstraZeneca). After the loading dose, all patients had their platelet reactivity assessed by VerifyNow. The researchers hypothesized that there was a potential drug-drug interaction between the currently recommended antiplatelet therapies and morphine in this patient population.

Ninety-five patients (32%) also received morphine. Those patients had a higher incidence of vomit compared with patients who did not receive morphine (15% vs. 2%; P=.001).

Two hours after the loading dose, P2Y12 reactivity unit was 187 in patients who received morphine compared with 133 in patients who did not receive morphine (P<.001). This difference in P2Y12 reactivity units persisted after the researchers excluded patients with vomit (P<.0001), according to the results.

Also at 2 hours, the researchers observed high residual platelet reactivity (P2Y12 reactivity units ≥208) in 53% of patients who received morphine compared with 29% in patients who did not receive morphine (P<.001). No difference was reported based on prasugrel or ticagrelor use, according to the results.

Morphine use (OR=2.91; 95% CI, 1.71-4.97) and age (OR=1.03; 95% CI, 1.01-1.05) were identified as independent predictors of high residual platelet reactivity at 2 hours. After the researchers performed propensity score adjustment, the association between morphine and high residual platelet reactivity persisted.

Disclosure: The researchers report no relevant financial disclosures.

Source: www.healio.com