Effects of Specific Cycloxygenase- 2 Inhibition on the Renal Functions of Elderly Patients with Renal Function Impairment

Overview

Background.
Elderly patients suffering from nociceptive pain of locomotive organs and concomitantly from renal impairment represent a target population for painkilling drugs. That is why they are predisposed to nephrotoxic effects non-steroidal anti-inflammatory drugs. The aim of our study was to evaluate cycloxygenase-2 (COX-2) inhibition effect on renal function in elderly with moderate impairment of renal function. 

Methods and Results.
Based on 24-h urine collection we assessed creatinine clearance (C_Cr), fractional excretion of sodium (FE_Na), potassium (FE_K), chloride (FE_Cl), osmotic active solutes (FE_OSM) and 24h urinary excretion of prostaglandin PGE2 and PGF_2α. Under conditions of sub-maximal water load fractional excretion of electrolytes, inulin clearance (C_in), serum cystatin C (S_cyst) were assessed. In addition basal and stimulated plasma renin activity (PRA) and plasma aldosteron (P_aldo) were examined. Using comparison of parameters before and at the end of 7-days rofecoxib treatment we found out C_in 0,82±0,34 vs 0,74±0,18 ml/s/1,73 m2, FE_Na 1,0±0,3 vs 1,2±0,4 (p=0,02), FE_OSM 2,9±0,7 vs 3,7±1,2 % (p=0,03), U_PGE2αV 663±528 vs 414±195 (p=0,059), U_PGF2V (559±625) vs 205±174 ηg/24h (p=0,02), stimulated PRA 0,94±0,73 vs 0,4±0,27 ±pg/l/h (p=0,019), P_aldo 104,56±50,15 vs 56,94±27,08 ηg/l/h (p=0,008). 

Conclusions.
Short-term COX-2 inhibition in patients with moderate renal impairment was associated with significant decrease of tubular transport of sodium, without changing GFR and water excretion. 

Key words:
coclooxygenase-2 inhibition, renal function, renal insufficiency.