There are some studies that have shown that NSTEMI patients have done worse when administered opioids. Most studies were not well controled and the exact mechanism was not clear. This study adds a biological mechanism to these fidnings.
Hobl et al. showed clopidogre concentrations delayt peak yhours, have overall decrease AUC and actually decrease active metabolites when morphine is administered IV. Morphine may not be the right choice in any ACS that receives clopidogrel.
References
Hobl et al. Morphine Decreases Clopidogrel Concentrations and Effects: A Randomzed Double-Blid, Placebo-Controlled Trial. Journal of the American College of Cardiology 2014; 63(7): 630-635.
