The Editorial Executive Committee welcomes letters, which should be less than 250 words. Before a decision to publish is made, letters which refer to a published article may be sent to the author for a response. Any letter may be sent to an expert for comment. When letters are published, they are usually accompanied in the same issue by their responses or comments. The Committee screens out discourteous, inaccurate or libellous statements. The letters are sub-edited before publication. Authors are required to declare any conflicts of interest. The Committee's decision on publication is final.
Letter to the Editor
The review on the new antiplatelet drugs (Aust Prescr 2014;37:182-6) was very useful and timely. However, one important aspect not mentioned was the influence of smoking status on drug efficacy. Smokers have an enhanced response to clopidogrel – the so-called smokers’ paradox.1
A recent meta-analysis concluded that the clinical benefit of clopidogrel in reducing cardiovascular events was seen primarily in smokers (25% risk reduction compared to controls), with little benefit in non-smokers (8% reduction).2
Prasugrel and ticagrelor were 47% and 36% more effective respectively than clopidogrel in smokers. However, in non-smokers the risk reduction was a modest 15% and 18% respectively compared with controls.
It would be helpful if the authors could comment on the clinical significance of these findings and their implications for drug selection and dosing. For example, is clopidogrel a suitable choice for non smokers and should they receive larger doses to improve efficacy? Should prasugrel and ticagrelor replace clopidogrel in smokers who quit? Are smokers at higher risk of major bleeds from these antiplatelet drugs?
Tobacco treatment specialist
The Sydney Clinic Consulting Rooms
Colin Mendelsohn has received payments for consultancy, educational presentations, travel and related expenses from Pfizer Australia, GlaxoSmithKline and Johnson & Johnson Pacific.
- Swiger KJ, Yousuf O, Bliden KP, Tantry US, Gurbel PA. Cigarette smoking and clopidogrel interaction. Curr Cardiol Rep 2013;15:361.
- Gurbel PA, Baker BA, Bailey WL, Bliden KP, Tantry US. Unravelling the smokers’ paradox: cigarette smoking, high-risk coronary artery disease and enhanced clinical efficacy of oral P2Y₁₂ inhibitors. Thromb Haemost 2014;111:1187-90.
- Cornel JH, Becker RC, Goodman SG, Husted S, Katus H, Santoso A. Prior smoking status, clinical outcomes, and the comparison of ticagrelor with clopidogrel in acute coronary syndromes-insights from the PLATelet inhibition and patient Outcomes (PLATO) trial. Am Heart J 2012;164:334-342.
- Gurbel PA, Bliden KP, Logan DK, Kereiakes DJ, Lasseter KC, White A. The influence of smoking status on the pharmacokinetics and pharmacodynamics of clopidogrel and prasugrel: the PARADOX study. J Am Coll Cardiol 2013;62:505-12.
- Gagne JJ, Bykov K, Choudhry NK, Toomey TJ, Connolly JG, Avorn J. Effect of smoking on comparative efficacy of antiplatelet agents: systematic review, meta-analysis, and indirect comparison. BMJ 2013;347:0.
- Cao C, Indraratna P, Ang SC, Manganas C, Park J, Bannon PG. Should clopidogrel be discontinued before coronary artery bypass grafting for patients with acute coronary syndrome? A systematic review and meta-analysis. J Thorac Cardiovasc Surg 2014;148:3092-8.
- Ye Y, Xie H, Zhao X, Zhang S. Smoking and prasugrel. Int J Cardiol 2013;168:1590-1.
- van Werkum JW, Heestermans AA, Zomer AC, Kelder JC, Suttorp MJ, Rensing BJ. Predictors of coronary stent thrombosis: the Dutch Stent Thrombosis Registry. J Am Coll Cardiol 2009;53:1399-409.