P-228: A comparative study of celecoxib versus diclofenac on blood pressure control and renal function in hypertensive African Americans and Hispanics: A randomized crossover study

Cyclooxygenase 2 enzyme (COX-2) inhibitors are tauted to have fewer adverse effects on blood pressure (BP) control and renal function compared to nonsteroidal anti-inflammatory agents (NSAIDs). To test the hypothesis that a selective COX-2 inhibitor does not affect BP or glomerular filtration rate (GFR) as much as an NSAID, we compared the effects of celecoxib (C)-200 mg daily, a COX-2 inhibitor to diclofenac (D)-75 mg bid, an NSAID. Using a randomized, cross over design, 20 participants (14 African-American/6 Hispanic; 12 female/8 male; mean age 58.5±8) with osteoarthritis, microalbuminuria (MA) and hypertension were studied over a three month period (one month on each treatment) separated by two two week washout periods. GFR was assessed using iohexol clearance, MA using spot urine albumin:creatinine ratios and blood pressure using 24 hour ambulatory monitoring (ABPM). All participants had their BP and arthritis meds stopped at study entry, and placed on the ACE inhibitor, trandolopril (T), titrating to a BP less than 140/90 mmHg, using a thiazide diuretic,if needed. After two weeks on BP treatment participants were randomization to either C or D and followed for a month, when GFR, BP, pain relief and MA were assessed. A washout period ensued for arthritis meds and they were crossed over to the other agent and all studies repeated. Data were analyzed per drug randomization. Pain relief was comparable between agents. Systolic BP changes from baseline were not significantly different between groups at either 9 to 12 hours (3±1 ΔmmHg, D vs 2±1 ΔmmHg, C;P=0.31) or 24 hours after dosing (3±2 ΔmmHg, D vs -2±2 ΔmmHg, C;P=0.06). This trend at 24 hours can be explained by differences in the pharmacokinetics and pharmacodynamics of the different agents. Other similarities and differences were as follows: Differences between groups occurred in ankle edema (P=0.006), where D had greater increases to C, and MA where D reduced the value. We conclude that no substantive differences exist in blood pressure or renal function changes between the COX-2 inhibitor, celecoxib and the NSAID diclofinac. (See Table) Celecoxib (200 mg/d)-n = 20 Diclofenac (75 mg/bid)-n = 20 Variable T- predrug T- postdrug T- predrug T- postdrug 24 hr. Diastolic ABPM (mmHg) 78 ± 11 75 ± 8 78 ± 7 81 ± 10 GFR (ml/min) 92 ± 31 96 ± 35 95 ± 31 93 ± 29 MA (mg/d) 13 ± 21 15 ± 38 13 ± 16 7 ± 16* Ankle Edema (cm.) 13 ± 3 13 ± 12 12 ± 3 14 ± 3* *P < 0.05 compared to pre-value.