Can diclofenac (Nonsteroidal Anti-Inflammatory Drug (NSAID)) cause elevated blood pressure (hypertension)?

Diclofenac and Blood Pressure Elevation

Yes, diclofenac can cause elevated blood pressure (hypertension), with studies showing it increases mean blood pressure by approximately 5 mm Hg and carries a higher cardiovascular risk compared to other NSAIDs. 1

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
• Diclofenac demonstrates more pronounced COX-2 inhibition compared to other NSAIDs, which correlates with greater blood pressure elevation and heart rate reduction 2
• 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) 1
• 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 1

Cardiovascular Impact

• Diclofenac can increase mean blood pressure by an average of 5 mm Hg while taking the medication 1
• 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 1
• The FDA drug label for diclofenac includes a black box warning about increased risk of cardiovascular thrombotic events, which can be fatal 3

Risk Factors and Monitoring

• Patients with cardiovascular disease or risk factors for cardiovascular disease are at greater risk for diclofenac-induced blood pressure elevation 1
• The risk of hypertension and cardiovascular events increases with duration of use 3
• Patients taking angiotensin-converting enzyme (ACE) inhibitors, thiazide diuretics, or loop diuretics may have impaired response to these therapies when taking diclofenac 3
• Blood pressure should be monitored during the initiation of diclofenac treatment and throughout the course of therapy 3

Clinical Recommendations

• For patients requiring NSAID therapy who have hypertension or cardiovascular risk factors, naproxen is a safer alternative to diclofenac based on cardiovascular risk profiles 4
• If diclofenac must be used, it should be prescribed at the lowest effective dose for the shortest duration possible to minimize cardiovascular risk 4
• Consider co-administration of misoprostol with diclofenac in salt-sensitive hypertensive patients, as it may attenuate diclofenac-induced blood pressure elevation 5
• Avoid diclofenac in patients with congestive heart failure unless benefits are expected to outweigh risks 3
• Monitor renal function in patients with renal or hepatic impairment, heart failure, dehydration, or hypovolemia during diclofenac use 3

Special Considerations

• 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
• Diclofenac may blunt the cardiovascular effects of several therapeutic agents used to treat hypertension (e.g., diuretics, ACE inhibitors, or angiotensin receptor blockers) 3
• Some studies suggest that calcium channel blockers like nifedipine may maintain blood pressure control even when co-administered with diclofenac, though this finding requires further validation 6