Theophylline for the prevention of radiocontrast nephropathy: a meta-analysis

Background. Radiocontrast nephropathy is a common cause of acute renal failure in hospitalized patients. Several studies have examined the capacity of theophylline or aminophylline to prevent radiocontrast nephropathy, with conflicting results. We conducted a meta-analysis of published randomized controlled trials to determine if the pre-procedural administration of theophylline or aminophylline prevents radiocontrast-induced declines in kidney function. Methods. We searched MEDLINE, EMBASE, the Cochrane Collaboration Database, bibliographies of retrieved articles, and consulted with experts to identify relevant studies. Randomized controlled trials of theophylline or aminophylline in hospitalized patients receiving radiocontrast were Included. Studies were excluded if they did not report changes in serum creatinine or creatinine clearance within 48 h after radiocontrast exposure. Results. Seven randomized controlled trials satisfied all inclusion criteria and were included in the analysis (pooled sample size n = 480). The difference in mean change in serum creatinine was 11.5 mumol/l (95% confidence intervals 5.3-19.4 mumol/l, P = 0.004) lower in the theophylline- or aminophylline-treated groups than controls. One participant (0.6%) required dialysis. Conclusions. Prophylactic administration of theophylline or aminophylline appears to protect against radiocontrast-induced declines in kidney function. Whether these agents reduce the proportion of patients who experience large decrements in serum creatinine concentration, or require dialysis, is unknown.