Diclofenac is the most widely used NSAID in low income countries. It has a market share roughly equal to the combined market share of ibuprofen, naproxen, and mefenamic acid. Like Cox-2 inhibitor refocoxib, even Diclofenac is also associated with increased risk of MI by 38%
Diclofenac has increased risk of heart attack even in small doses, and this risk increases with increasing dose of Diclofenac. There is no safe dose of Diclofenac.
Relatively higher inhibition of COX-2 inhibition compared to COX-1inhibition maybe the reason for increased cardiovascular risk of MI and stroke.
Unlike Diclofenac Smaller doses of Naproxen, Ibuprofen and Celecoxib prescribed over the counter are not associated with increased risk of heart attack but increasing doses used in clinical trials are associated with cardiovascular risk.
Dr David Henry (Institute for Clinical Evaluative Sciences, Toronto, ON) conducted the reviewpublished online February 12, 2013 in PLoS Medicine, states that, he has written to WHO to remove Diclofenac from essential medicine list and has advised to use Naproxen instead of Diclofenac.
Dr Gabriel Steg (Centre Hospitalier Bichaut-Claude Bernard, Paris, France) states that it is class effect of NSAID’s not just Diclofenac. Probably Diclofenac may be associated with more cardiovascular risk than other NSAIDs