Clopidogrel adverse effects

Clopidogrel has fewer adverse effects than ticlopidine and is rarely associated with neutropenia. Thrombotic thrombocytopenic purpura associated with clopidogrel has been reported. Because of its superior side effect profile and dosing requirements, clopidogrel is preferred over ticlopidine. The antithrombotic effects of clopidogrel are dose-dependent within 5 hours after an oral loading dose of 300 mg, 80% of platelet activity will be inhibited. The maintenance dose of clopidogrel is 75 mg/d, which achieves maximum platelet inhibition. The duration of the antiplatelet effect is 7-10 days. 

The adverse effects of clopidogrel have been reviewed (3). 

Ticlopidine is a thienopyridine derivative with potent antiplatelet activity associated with inhibition of ADP-induced platelet aggregation. It was first used in Europe in 1978 in the secondary prevention of stroke and coronary events, the treatment of peripheral vascular disease, and after vascular stent placement. However, the use of ticlopidine has been progressively restricted in some countries because of its serious adverse effects. It has largely been superseded by clopidogrel. 

The efficacy of clopidogrel as an antiplatelet agent in atherothrombotic disorders was demonstrated in the CAPRIE trial. In this study of more than 19,000 patients with a history of either myocardial infarction (MI), stroke, or peripheral arterial disease (PAD), clopidogrel 75 mg/day was compared with aspirin 325 mg/day for its ability to decrease MI, stroke, or cardiovascular death. In the final analysis, clopidogrel was slightly (8% relative risk reduction [RRR]) more effective than aspirin (p =. 043) and had a similar incidence of adverse effects. It is not associated with the blood dyscrasias (neutropenia) common with its congener, ticlopidine, and is used widely in patients with atherosclerosis. 

Adverse effects (see Section VI, Drugs for Inflammatory and Related Disorders) Ticlopidine and clopidogrel... 

Floyd JS, Kaspera R, Marciante KD, Weiss NS, Heckbert SR, Lumley T, et al. A screening study of drug-drug interactions in cerivastatin users an adverse effect of clopidogrel. Clin Pharmacol Ther 2012,-91(5) 896-904. 

Platelet inhibitors are widely used in the treatment and prevention of coronary artery disease. In addition to acetic salicylic acid (ASA), two major groups of platelet inhibitors are used phosphodiesterase inhibitors, including dipyridamole, and thienopyridines. Clopidogrel is the most widely used antiplatelet agent and in combination with ASA, it is the standard-of-care (SoC) for acute coronary s5mdromes and percutaneous coronary interventions. However, the mechanisms of action include pathways that affect the metabolic activity of bone cells and pharmacologic modulation of these pathways may have adverse effects on the bones. 

Clopidogrel STEMI (10), NSTEMI (11) Elective PCI (l 2) 300 mg loading dose (10-12) unless PCI to be performed within eight hours in which case 600 mg recommended As effective as ticlodipine in preventing stent thrombosis (9) Reduced incidence of adverse hematologic reactions compared to ticlodipine (9)... 

Antiplatelet therapy plays a key role in the treatment of ACS, such as Ml. Aspirin has been shown to decrease overall mortality and reinfarction and is recommended for all patients in this setting unless contraindicated. Aspirin should be given at the lowest effective dose, to ensure efficacy and to limit adverse reactions. If aspirin is contraindicated or not tolerated, thienopyridines (clopidogrel or ticlopidine) may be used. Comparisons of oral antiplatelet agents are summarized in Thumbnail. 

Ginkgo biloba has been associated with platelet, bleeding and clotting disorders and there are isolated reports of serious adverse reactions after its concurrent use with antiplatelet drugs such as aspirin, clopidogrel and ticlopidine. An animal study su ests that Kangen-Katyu may also enhance the antiplatelet and antithrombotic effects of ticlopidine. 

Bhurke SM, Martin BC, Li C, Franks AM, Bursae Z, Said Q. Effect of the clopidogrel-proton pump inhibitor drug interaction on adverse cardiovascular events in patients with acute coronary syndrome. Pharmacotherapy 2012 32 809-18. 

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