Can diclofenac (NSAID) be given to a patient with hypertension?

Diclofenac Should Generally Be Avoided in Patients with Hypertension

Diclofenac and other NSAIDs should be used with extreme caution—or avoided entirely—in patients with hypertension due to their well-documented ability to elevate blood pressure, worsen blood pressure control, and increase cardiovascular risk. 1, 2

Evidence from Guidelines and FDA Labeling

Cardiovascular and Blood Pressure Risks

• The FDA black box warning for diclofenac explicitly states that NSAIDs may cause increased risk of serious cardiovascular thrombotic events, myocardial infarction, and stroke, which can be fatal, with risk increasing with duration of use and in patients with cardiovascular disease or risk factors. 1, 2

• NSAIDs including diclofenac can lead to new onset of hypertension or worsening of preexisting hypertension, either of which may contribute to increased incidence of cardiovascular events. 2

• The American Heart Association scientific statement explicitly recommends that nonsteroidal anti-inflammatory drugs should be used with caution in heart failure patients given their effects on blood pressure, volume status, and renal function. 1

Mechanism and Clinical Impact

• Diclofenac interferes with blood pressure control by blocking prostaglandin synthesis, which normally promotes vasodilation and sodium excretion. 3

• Patients taking ACE inhibitors, thiazide diuretics, or loop diuretics may have impaired response to these antihypertensive therapies when taking NSAIDs. 2

• Blood pressure should be monitored during initiation of NSAID treatment and throughout the course of therapy. 2

Quantifying the Risk

Blood Pressure Elevation

• Meta-analyses show that NSAIDs raise mean arterial pressure by approximately 5 mm Hg, though this may be higher in elderly patients and those with pre-existing hypertension. 3

• In a prospective study of hypertensive patients, diclofenac increased mean arterial pressure by 5.0 ± 1.0 mm Hg and decreased renal plasma flow by 40.5 ml/minute. 4

• A comparative study found diclofenac raised systolic blood pressure by a mean of 8.5 mm Hg in hypertensive patients already on antihypertensive treatment. 5

Cardiovascular Events

• Meta-analysis of randomized controlled trials showed diclofenac increased vascular events with a relative risk of 1.63 (95% CI 1.12-2.37) compared to placebo. 1

• Observational studies demonstrated diclofenac increased risk of recurrent MI (RR 1.54,95% CI 1.23-1.93) and mortality (RR 2.40,95% CI 2.09-2.80). 1

Clinical Decision Algorithm

When Diclofenac Must Be Avoided (Absolute or Strong Relative Contraindications)

• Patients with severe heart failure (NYHA class III-IV) should avoid diclofenac unless benefits clearly outweigh risks of worsening heart failure. 1, 2

• Patients with uncontrolled hypertension (BP ≥160/100 mm Hg or above target despite treatment) should not receive diclofenac until blood pressure is adequately controlled. 6

• Patients with advanced renal disease should avoid diclofenac unless benefits outweigh risk of worsening renal function. 2

• Patients with coronary artery disease or high cardiovascular risk should avoid diclofenac given its particularly high cardiovascular risk profile among NSAIDs. 1, 7

If Diclofenac Must Be Used Despite Hypertension

• Blood pressure must be well-controlled (<140/90 mm Hg) before considering NSAID therapy. 6

• Use the lowest effective dose for the shortest duration possible to minimize cardiovascular and renal risks. 2

• Monitor blood pressure within the first week of treatment and regularly thereafter, as blood pressure elevation typically occurs early. 2, 3

• Monitor for signs of fluid retention, edema, weight gain, and worsening renal function (serum creatinine and potassium). 1, 2

• Ensure adequate hydration before initiating therapy, particularly in elderly or volume-depleted patients. 2

Safer Alternatives for Pain Management

First-Line Alternative

• Acetaminophen should be considered as first-line for acute pain management in patients with hypertension, as it lacks significant effects on blood pressure. 6

If Stronger Analgesia Required

• Carefully titrated opioids may be safer than NSAIDs in patients with severe uncontrolled hypertension. 6

• Among NSAIDs, sulindac and possibly aspirin appear less problematic regarding blood pressure effects compared to other NSAIDs including diclofenac. 3

Protective Co-Administration

• If diclofenac must be used, coadministration of misoprostol (200 mcg twice daily) can attenuate the blood pressure elevation and renal vasoconstrictive effects, reducing mean arterial pressure increase by 3.3 mm Hg. 4

Critical Monitoring Parameters

During NSAID Therapy in Hypertensive Patients

• Blood pressure should be checked within 3-7 days of starting diclofenac, then weekly for the first month, as most blood pressure elevations occur within the first 2 weeks. 2, 3

• Assess for orthostatic hypotension in elderly patients, particularly those on multiple antihypertensive agents. 1

• Monitor serum creatinine and potassium within 1-2 weeks of initiation, especially in patients taking ACE inhibitors, ARBs, or potassium-sparing diuretics. 2

• Watch for signs of fluid retention: peripheral edema, weight gain >2 kg, dyspnea, or worsening heart failure symptoms. 1, 2

Common Pitfalls to Avoid

• Do not assume that because a patient's blood pressure is controlled on antihypertensive medications, diclofenac is safe—NSAIDs can overcome the effects of antihypertensive therapy. 2

• Do not prescribe diclofenac without explicitly counseling patients about cardiovascular risks and the need for blood pressure monitoring. 1, 2

• Do not combine diclofenac with other NSAIDs or high-dose aspirin (>81 mg), as this increases gastrointestinal and cardiovascular toxicity without additional benefit. 2

• Do not ignore the interaction between diclofenac and antihypertensive medications—the effectiveness of ACE inhibitors, ARBs, beta-blockers, and diuretics may all be diminished. 2