In case of low glomerular filtration rate (GFR), the procedure depends on whether the dose that can be given is larger or less than the needed dose. The main alternatives in people with a risk of<unk>  are: * Adjustment of the radiocontrast dose * Treating or mitigating risk factors * Using no intravenous<unk>  for the investigation. * Switching to another modality such as ultrasonography or MRI. Dose adjustment According to European guidelines, the ratio of the<unk>  dose (in grams of iodine) divided by the absolute estimated glomerular filtration rate (GFR) should be less than 1.1 g/(ml/min) for intra-arterial<unk>  medium administration with first-pass renal exposure (not passing lungs or peripheral tissue before reaching the kidneys). Swedish guidelines are more restrictive, recommending a ratio of less than 0.5 g/(ml/min) in patients with risk factors and irrespective of route of administration, and even more caution in first-pass renal exposure. Treating or mitigating risk factors Hydration by drinking or intravenous volume expander, either before or after<unk>  administration, decreases the risk of<unk> . Evidence also supports the use of N-acetylcysteine with intravenous saline among those getting low molecular weight<unk> . The use of statins with N-acetylcysteine and intravenous saline is also supported. * Oral hydration may be as effective as the intravenous route for volume expansion to prevent<unk> , according to a review in 2013. * Adenosine antagonists such as the methylxanthines theophylline and aminophylline, may help although studies have conflicting results. * N-acetylcysteine (NAC) by mouth twice a day, on the day before and of the procedure if creatinine clearance is estimated to be less than 60 mL/min 1.00 mL/s) may reduce risk. Some authors believe the benefit is not overwhelming. A systematic review concluded that NAC is "likely to be beneficial" but did not recommend a specific dose. * Ascorbic acid may be protective against<unk> , according to a systematic review of randomized controlled trials.
Contrast-induced nephropathy
Analgesic nephropathy
Reflux nephropathy
Shunt nephritis
IgA nephropathy
Diabetic nephropathy
Benign nephrosclerosis
Acute uric acid nephropathy