Background: The use of N-acetylcysteine or theophylline in specific subgroups of patients has been suggested to reduce the incidence of contrast-induced nephropathy (CIN) in patients undergoing angiographic procedures. Our purpose was to compare the use of N-acetylcysteine versus N-acetylcysteine + theophylline for the prevention of CIN.
Materials and methods: We randomized 217 patients with estimated glomerular filtration rate (eGFR) (calculated by Modification of Diet in Renal Disease formula) between 30 and 60 mL min(-1) 1.73 m(-2) who were undergoing coronary angiography to three prophylactic treatment groups: Group 1: Intravenous hydration with isotonic saline (1 mL kg(-1) h(-1) for 12 h before and after contrast, n = 72). Group 2: Intravenous hydration with isotonic saline (1 mL kg(-1) h(-1) for 12 h before and after contrast)+ N-acetylcysteine (600 mg p.o. twice daily the preceding day and the day of angiography, n = 73). Group 3: Intravenous hydration with isotonic saline (1 mL kg(-1) h(-1) for 12 h before and after contrast)+ N-acetylcysteine + theophylline (600 mg N-acetylcysteine p.o. and 200 mg theophylline p.o. twice daily for the preceding day and the day of angiography, n = 72). The incidence of CIN (0.5 mg dL(-1) increase in serum creatinine from the baseline value 48 h after intravascular injection of contrast) was compared in three groups.
Results: Of the 217 patients, 12 patients (5.5%) experienced CIN. Five patients (6.9%) in group 1, seven patients (9.6%) in group 2 and zero (0%) patients in group 3 experienced CIN (P < 0.033).
Conclusion: Among patients with eGFR between 30 and 60 mL min(-1) 1.73 m(-2) undergoing coronary angiography, oral administration of N-acetylcysteine + theophylline in addition to saline hydration has a beneficial effect in the prevention of CIN.