Internal and emergency medicine
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The interaction of ADP with its platelet receptor P2Y12 plays a crucial role in platelet activation and thrombogenesis. This article reviews the pharmacology and clinical trials of specific antagonists of P2Y12. Clopidogrel is a thienopyridine with proven antithrombotic efficacy, but it has some important drawbacks: (a) it is a pro-drug that needs to be metabolized to its active metabolite; (b) it has a delayed onset and offset of action and (c) there is high inter-individual variability in pharmacological response. ⋯ Cangrelor is not superior to clopidogrel in preventing thrombotic events in patients undergoing PCI. Ticagrelor is superior to clopidogrel in preventing major adverse cardiac events in ACS patients, but, like prasugrel, is associated with a higher frequency of non-CABG-related bleeding complications. A shorter period of drug discontinuation before surgery is necessary in ticagrelor-treated patients compared to clopiodgrel-treated patients to limit the severity of post-surgical bleeding.
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Chronic headaches represent a significant burden for the affected individuals and for the society, and a major challenge for successful care. Among the various types of chronic headaches, those that are associated with medication overuse (medication-overuse headache, MOH) are of particular importance because of the large proportion of patients who complain of this condition and their poor outcome. Most patients with MOH had migraine as primary headache. ⋯ Although the pathophysiology of MOH is unknown, recent studies hypothesize that plastic changes in specific pain areas of the central nervous system are main contributors to establishing MOH. Not infrequently, drug overuse is associated with habituation and failure of previously effective medications. Finally, treatment of MOH is poorly evidence based and mostly relies on clinical experience and belief.