The role of theophylline in contrast-induced nephropathy: a case-control study.
BACKGROUND
Various strategies for the prevention of contrast-induced nephropathy (CN) have been studied, with conflicting results. Adenosine may play an important role in the pathogenesis of CN. This study prospectively assessed the role of oral theophylline in the prevention of CN.


METHODS
We randomized into two groups 70 patients with diabetes mellitus who were undergoing coronary angiography (CAG) with high-osmolar contrast media. Group I (n=35) underwent routine CAG, and group II (n=35) received oral theophylline 200 mg b.d. 24 h before and for 48 h after CAG. Serum Na(+), K(+), blood urea nitrogen (BUN), creatinine, osmolality, glomerular filtration rate (GFR) and urinalysis were performed before and after CAG. The (99m)Tc-DTPA-clearance method was used to assess GFR.


RESULTS
Following angiography, patients in the control group showed a significant rise in serum creatinine (1.19+/-0.23 vs 1.44+/-0.32 mg/dl, P=0.003) and BUN (13.95+/-2.61 vs 17.55+/-3.9 mg/dl, P=0.01) along with a fall in GFR (85.4+/-14.7 vs 66.85+/-14.8 ml/min, P=0.008). The mean percentage fall in GFR was 35.8%. There was no significant change in serum creatinine (1.16+/-0.18 vs 1.24+/-0.21 mg/dl), BUN (12.8+/-3.36 vs 14.8+/-2.5 mg/dl) and GFR (86.8+/-15.8 vs 80.3+/-16.0 ml/min) in those receiving theophylline. No patient in the theophylline group had a >25% rise in serum creatinine, compared with 7/35 in the control group (P=0.017). In the control group, 11/35 (31%) developed CN, as demonstrated by a >/=25% fall in GFR, while only one patient in the theophylline group had a fall in GFR (P=0.004). None of the pre-angiographic variables could predict the development of CN.


CONCLUSIONS
Following the use of high-osmolar contrast media for routine CAG, CN may develop in 31% of diabetic patients. Patients who received prophylactic oral theophylline had a significantly lower risk of CN than those who did not.
Kapoor
Aditya
A
Department of Cardiology, Sanjay Gandhi PGIMS, Lucknow, India. akapoor@sgpgi.ac.in
Kumar
Sudeep
S
Gulati
Sanjeev
S
Gambhir
Sanjay
S
Sethi
Ravindra S
RS
Sinha
Nakul
N
D000284:Administration, Oral; D000328:Adult; D000368:Aged; D001806:Blood Urea Nitrogen; D016022:Case-Control Studies; D003287:Contrast Media / Q000009:adverse effects*; D017023:Coronary Angiography; D003404:Creatinine / Q000097:blood; D003920:Diabetes Mellitus / Q000000981:diagnostic imaging; D003974:Diatrizoate Meglumine / Q000009:adverse effects*; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006801:Humans; D015994:Incidence; D007674:Kidney Diseases / Q000139:chemically induced* / Q000453:epidemiology / Q000517:prevention & control*; D008875:Middle Aged; D013806:Theophylline / Q000008:administration & dosage*
D003287:Contrast Media; D003974:Diatrizoate Meglumine; D003404:Creatinine; D013806:Theophylline