The influence of naloxone on pharmacokinetics and pharmacodynamics of ticagrelor in patients with unstable angina pectoris receiving concomitant treatment with morphine — a protocol of a randomized trial

Rapid platelet inhibition plays pivotal role in contemporary treatment of patients presenting with acute coronary syndromes. Morphine, the most commonly used analgesic has been proven to impair both absorption and onset of action of P2Y12 receptor inhibitors, which can be described as “the morphine effect”. Most negative effects of morphine are caused by its undesirable influence on gastrointestinal tract. We hypothesized that naloxone, widely administered intravenous opioid reversing drug, may turn out to be beneficial if given orally in acute coronary syndrome patients previously treated with morphine. Therefore, a phase IV, randomized pilot study was designed so as to evaluate the impact of naloxone administration on pharmacokinetics and pharmacodynamics of P2Y12 inhibitor, ticagrelor in unstable angina patients. A group of 30 consecutive unstable angina patients treated with ticagrelor and morphine will be randomized in a 1:1 ratio into the study arms. To the best of our knowledge, no such approaches to overcome negative influence of morphine in acute coronary syndrome patients have been described in literature so far.