Degree of Cyclooxygenase-2 Inhibition Modulates Blood Pressure Response

Area of Science:

• Pharmacology
• Cardiovascular Research
• Drug Safety

Background:

• Previous clinical trials on nonsteroidal anti-inflammatory drugs (NSAIDs) and cardiovascular risk did not standardize doses for equivalent cyclooxygenase (COX) inhibition.
• The varying degrees of COX-2 inhibition among NSAIDs may influence their cardiovascular safety profiles.

Purpose of the Study:

• To compare the cyclooxygenase (COX) target inhibition and blood pressure (BP) response between celecoxib and naproxen.
• To investigate the relationship between COX-2 inhibition and BP changes.

Main Methods:

• A double-blind, crossover study involving 16 healthy participants treated with celecoxib (200 mg/d), naproxen (500 mg/d), or placebo for 7 days.
• COX inhibition was assessed using ex vivo whole blood assays and in vivo urinary metabolite quantification (COX-1 and COX-2).
• Ambulatory blood pressure was monitored throughout the final dosing interval.

Main Results:

• Both NSAIDs inhibited COX-2 activity, but naproxen demonstrated significantly greater inhibition (62.9%) compared to celecoxib (35.7%).
• Naproxen also showed greater inhibition of in vivo prostacyclin formation (COX-2 marker) than celecoxib.
• Naproxen significantly increased mean arterial, systolic, and diastolic blood pressure compared to celecoxib and placebo, with BP increases correlating with COX-2 inhibition levels.

Conclusions:

• The degree of cyclooxygenase-2 (COX-2) inhibition varies significantly between naproxen and celecoxib at standard doses.
• Naproxen's greater COX-2 inhibition is associated with a more pronounced increase in blood pressure.
• Future cardiovascular risk assessments of NSAIDs should account for pharmacodynamic differences, including COX inhibition levels and patient-specific factors.