Diclofenac and Blood Pressure Elevation

Mechanism and Evidence

All NSAIDs, including diclofenac, have the potential to aggravate hypertension, congestive heart failure, and edema by inhibiting prostaglandin production, which affects renal function and vascular tone 1
Meta-analyses show diclofenac has a relative risk of 1.63 (95% CI 1.12-2.37) for vascular events compared to placebo, significantly higher than naproxen's risk profile (RR 0.92, 95% CI 0.67-1.26) 3
Diclofenac lies on the more COX-2 selective end of the spectrum of COX inhibition, explaining its higher thrombotic risk profile similar to selective COX-2 inhibitors 4

Diclofenac can increase mean blood pressure by an average of 5 mm Hg while taking the medication 2
The blood pressure-elevating effect contributes to increased cardiovascular morbidity, including worsened congestive heart failure and adverse cardiovascular events such as myocardial infarction 1
Diclofenac has been associated with a 54% increased risk of recurrent myocardial infarction (RR 1.54, 95% CI 1.23-1.93) and 140% increased mortality risk (RR 2.40, 95% CI 2.09-2.80) compared to placebo in registry studies 3

Patients with cardiovascular disease or risk factors for cardiovascular disease are at greater risk for diclofenac-induced blood pressure elevation 3

For patients requiring NSAID therapy who have hypertension or cardiovascular risk factors, naproxen is a safer alternative to diclofenac based on cardiovascular risk profiles 5
If diclofenac must be used, it should be prescribed at the lowest effective dose for the shortest duration possible to minimize cardiovascular risk 5

The combination of diclofenac with ACE inhibitors or angiotensin receptor blockers may increase the risk of renal complications and further impact blood pressure control 1