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South Asian Clinical Toxicology Research Collaboration NSAIDS in the ischaemic heart disease patient Andrew Dawson SACTRC Program Director University of.

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Presentation on theme: "South Asian Clinical Toxicology Research Collaboration NSAIDS in the ischaemic heart disease patient Andrew Dawson SACTRC Program Director University of."— Presentation transcript:

1 South Asian Clinical Toxicology Research Collaboration NSAIDS in the ischaemic heart disease patient Andrew Dawson SACTRC Program Director University of Peradeniya Sri Lanka

2 South Asian Clinical Toxicology Research Collaboration 2002 Medico-legal  13 November 2000 –Roxithromycin and celecoxib  25 November 2000 –generalised itchy rash ceased celecoxib  15 December 2000 –Restarted celecoxib  15 December 2000 –sudden onset of severe pain in her legs –acute thrombosis

3 South Asian Clinical Toxicology Research Collaboration Questions  whether an adverse reaction to celecoxib (Celebrex) was the cause of the rash?  can celecoxib can cause or increase the likelihood of thrombosis either directly or as a manifestation of a hypersensitivity reaction?  What was known in 2000 & in 2002?

4 South Asian Clinical Toxicology Research Collaboration Objectives  Putative mechanisms  What is the risk –What variables are important  “What to do” with an individual patient  Graphics –Grosser T, Fries S, Fitzgerald. Biological basis for the cardiovascular consequences of COX-2 inhibition. The Journal of Clinical Investigation Volume 116 Number 1 January 2006

5 South Asian Clinical Toxicology Research Collaboration  Mechanistic –Risk is largely explained by extent of relative inhibition of COX1 and COX2 –Basis was established before COX2 marketed  Extent of Risk –Drug Factors l Type, duration –Patient Factors l Underlying cardiovascular risk

6 South Asian Clinical Toxicology Research Collaboration 6 January 11, 2008 What’s a COX?  COX-1 is expressed in most tissues. Functions towards gastric cytoprotection, vascular homeostasis, platelet aggregation, and kidney function  COX-2 expressed in the brain, kidney, bone, and probably in the female reproductive system. Its expression at other sites (cardiovascular), increased during states of inflammation  Increased expression of COX-2 mRNA and protein has been noted in patients with hypertension, heart failure, and diabetic nephropathy 1

7 South Asian Clinical Toxicology Research Collaboration Membrane Phospholipids Arachidonic Acid Prostaglandins Thromboxanes Prostaglandins Prostacyclins endotoxins cycokines mitogens COX-1 Inhibited by NSAIDS COX-2 Inhibited by NSAIDS COX-2 inhibitors Induced

8 South Asian Clinical Toxicology Research Collaboration Cyclo oxygenase inhibiton

9 South Asian Clinical Toxicology Research Collaboration COX Inhibition

10 South Asian Clinical Toxicology Research Collaboration Relative Selectivity

11 South Asian Clinical Toxicology Research Collaboration 11 January 11, 2008 Mechanisms  COX-2 reduced prostaglandin I2 (PGI2 or prostacyclin) production by vascular endothelium with little or no inhibition of potentially prothrombotic platelet thromboxane A2  COX inhibition in general associated with elevations in blood pressure (<5 mm Hg elevations in systolic blood pressure)  COX-2 role in vascular remodelling

12 South Asian Clinical Toxicology Research Collaboration

13 Clinical Studies  Pre licencing Studies of COX 2 underpowered for vascular events  Postmarketing studies patients had variable baseline cardiac risk –Initially obscured & subsequently informed risk assessment

14 South Asian Clinical Toxicology Research Collaboration 14 January 11, 2008 CLASS and VIGOR trials  CLASS trial: –randomized double blinded 8000 adults with RA or OA. –GI Outcomes between celecoxib 400 bid (high dose) vs. diclofenac 75 od or ibuprofen 800 tid –Able to use ASA 325 –no significant increase risk MI with celecoxib  VIGOR study –randomized double blind looking at rofecoxib (50 od) vs 500 bid naproxen in RA –>8000 patients over median 9 months. –No use of ASA –significant risk of MI with rofecoxib (20 vs 4 events)  Why the difference? (a) Naproxen anti-platelet effects, bigger difference in rates vs. COX2i in CLASS (b) ASA in CLASS more protective than COX2i harmful in ischemic rates? (c) Rofecoxib prothrombotic via reduction of prostacyclin

15 South Asian Clinical Toxicology Research Collaboration 15 January 11, 2008 Rofecoxib: studies related to Ischemic events  APPROVe trial: –RCT 2586 patients rofecoxib (25 mg/day) or placebo –3 years.  Thrombotic events (MI, Stroke) –1.5 per 100 patient years (Active) vs 0.78 per 100 patient years(placebo) –RR 1.92, 95% CI  Assuming one year of Rx, for every 139 patients treated for a year, one additional cardiovascular event will occur.

16 South Asian Clinical Toxicology Research Collaboration 16 January 11, 2008 Rofecoxib: meta-analysis for Ischemic events  8 clinical trials  25,273 patients were randomly assigned to rofecoxib or a control (placebo or comparison NSAID)  2.24 RR of MI in rofecoxib group –(95% CI ).  Juni, P, Nartey, L, Reichenbach, S, et al. Risk of cardiovascular events and rofecoxib: cumulative meta- analysis. Lancet 2004; 364:2021. 

17 South Asian Clinical Toxicology Research Collaboration COX-2 inhibition in CABG  Ott E et al Efficacy and safety of the cyclooxygenase 2 inhibitors parecoxib and valdecoxib in patients undergoing coronary artery bypass surgery. J Thorac Cardiovasc Surg Feb;127(2):605

18 South Asian Clinical Toxicology Research Collaboration COX-2 inhibition in CABG  RR 3.7 Vascular Event –(95% CI 1.0 to 13.5)  Relative Aspirin resistance  Rapid emergence of cardiovascular hazard in high risk groups  Nussmeier N et al Complications of the COX-2 Inhibitors Parecoxib and Valdecoxib after Cardiac Surgery N Engl J Med 2005;352:

19 South Asian Clinical Toxicology Research Collaboration 19 January 11, 2008 Celecoxib: APC (adenomatous polyp prevention trial),  2035 patients RCT –Celecoxib (400 mg bid or 200 bid) or placebo, –33 month followup  Relative Risk Cardiovascular event –RR 2.6, 95% CI, Celecoxib 200 mg BD –RR 3.4, 95% CI, Celecoxib 400 mg BD  Dose effect in low risk population l Bertagnolli, MM, Eagle, CJ, Zauber, AG, et al. Celecoxib for the prevention of sporadic colorectal adenomas. N Engl J Med 2006; 355:873.

20 South Asian Clinical Toxicology Research Collaboration BMC Medicine 2005, 3:17

21 South Asian Clinical Toxicology Research Collaboration

22 Clinical Balance

23 South Asian Clinical Toxicology Research Collaboration Risk

24 Australian Drug Reaction Advisory Committee 2002  There may be an increased risk of cardiovascular and cerebrovascular disease with rofecoxib and celecoxib  The increase in risk seems to be higher in those with pre-existing cardiovascular disease  The risk appears to be greater with rofecoxib than with celecoxib, and appears to be dose related  Rofecoxib should not be used in doses exceeding the maximum approved dose (25 mg/day)  Cardiovascular risk should be evaluated before prescribing a coxib 24 January 11, 2008

25 South Asian Clinical Toxicology Research Collaboration COX Inhibitors Proven cardioprotective efficacyLow-dose aspirin (1a) Potential cardioprotective efficacy (inter-individual variablity) Naproxen (3a) Potential to decrease cardioprotective effect of low-dose aspirin Ibuprofen (3a) Flubiprofen (5) Indomethacin (5) Naproxen (5) Proven gastroprotective efficacy (COX -2 ) Rofecoxib (withdrawn) (1b) Lumiracoxib (FDA approval pending) (1b)

26 South Asian Clinical Toxicology Research Collaboration COX & low cardiovascular risk Chronic treatment low cardiovascular and low GI risk Naproxen (2b, 2a) Ibuprofen (2b, 2a) Chronic treatment low cardiovascular and high GI risk Naproxen + proton pump inhibitor (2b, 2a) Ibuprofen + proton pump inhibitor (2b, 2a) Diclofenac + proton pump inhibitor (2b, 2a) Possibly celecoxib (although GI advantage vs. tNSAID not proven) (3, 2)

27 South Asian Clinical Toxicology Research Collaboration Chronic treatment high cardiovascular and low GI risk Naproxen + Clopidogrel to avoid potential interaction with low-dose aspirin GI toxicity of this combination is likely = tNSAID + low-dose aspirin and may warrant addition of a proton pump inhibitor) (5) Ibuprofen + clopidogrel (see comment above) (5) Chronic treatment high cardiovascular and high GI risk Naproxen + proton pump inhibitor + clopidogrel (5) Ibuprofen + proton pump inhibitor + clopidogrel (5) COX & high cardiovascular risk

28 South Asian Clinical Toxicology Research Collaboration Thank you for attention Copy of the talk on

29 South Asian Clinical Toxicology Research Collaboration 29 January 11, 2008 COX2i: Heart Failure  Lancet 2004, Mamdani et al.: restrospective study examined incidence of heart failure in NSAID-naive older (66 years) individuals.  New prescriptions for rofecoxib, celecoxib, and nonselective NSAIDs were issued to 14,583, 18,908, and 5,391 patients, and heart failure in these groups compared to 100,000 controls.celecoxib  Crude rates of hospitalization for heart failure per 100 patient- years of exposure were 0.9 for the controls, 2.4 for the rofecoxib, 1.3 for the celecoxib, and 1.6 for the nonselective NSAID groups.  Relative risk of hospitalization with heart failure was significantly higher in those receiving rofecoxib than those receiving celecoxib (adjusted relative risk (RR) 1.8 versus 1.0, respectively).

30 South Asian Clinical Toxicology Research Collaboration  Mechanism based vascular remodeling may interact with a predisposition to hypertension and atherosclerosis in contributing to the gradual transformation of cardiovascular risk during extended periods of treatment with selective inhibitors of COX-2. (CircRes. 2005;96: )

31 South Asian Clinical Toxicology Research Collaboration


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