Recent developments in toxic nephropathy

Anti-inflammatory drugs and the kidney

Non-steroidal anti-inflammatory drugs (NSAIDs) and selective COX-2 inhibitors (coxibs) enjoy widespread use in clinical practice, leading to a remarkable frequency of unwanted renal side effects. In most cases, NSAID-induced acute renal failure or acute kidney injury is hemodynamically mediated. Clinical syndromes associated with NSAID use include acute renal failure, acute interstitial nephritis, worsening of chronic kidney disease (CKD), salt and water retention and hypertension. Careful monitoring of renal function is advisable in patients at increased risk such as elderly individuals with compromised cardiac reserve, and diabetics.

Prevention of Contrast Media–induced Nephrotoxicity after Angiographic Procedures

Contrast medium-induced nephrotoxicity (ie, contrast nephrotoxicity [CN]) remains an important complication of angiographic procedures. If administration of iodinated contrast medium is deemed necessary in patients at high risk of CN, volume expansion should be offered and the lowest possible dose of nonionic isosmolar dimeric or nonionic low-osmolar monomeric contrast medium should be used. Prophylactic administration of fenoldopam or acetylcysteine has not offered consistent protection against CN. Intravenous acetylcysteine could be considered in emergency situations. Recently, sodium bicarbonate infusion has been shown to reduce the risk of CN. Hemofiltration for several hours before and after contrast medium injection may offer good protection against CN in patients with advanced renal disease. Prophylactic hemodialysis does not offer any protection against CN.

Risks associated with the use of intravenous immunoglobulin

Although US immune globulin intravenous (human) (IGIV) products have been regarded as safe, it is important to recognize that many of the controlled clinical studies of IGIVs have been of modest size and have limited power to define the incidence of only the most common adverse events (AEs). A significant number of "postmarketing" serious AEs affecting renal, cardiovascular, CNS, integumentary, and hematologic organ systems have been reported. Variables potentially affecting the risk and intensity of adverse events associated with administration of IGIV include patient age, underlying condition, history of migraine, cardiovascular or renal disease, dose, concentration, rate of infusion, specific brand/formulation/excipients, and lot(s) of the particular IGIV product being administered. Each manufacturer's IGIV preparation is a unique product carrying its own specific evidence-based indications and safety profile. In view of the seriousness of potential adverse effects of IGIV products, and current lack of data surrounding their frequency, clinicians are advised to limit their prescription of these products for conditions for which efficacy is supported by adequate and well-controlled clinical trials. Prescribers should pay close attention to patient selection; consider the potential risk/benefit ratio vis-a-vis alternate therapies; and familiarize themselves with the identification, management, and proposed strategies to minimize the risks of IGIV.

Acute toxic renal failure

Acute renal failure (ARF) is a common problem in intensive care medicine. Even modest degrees of ARF not requiring dialysis treatment increase the risk of death approximately fivefold. Despite the widespread appreciation of the role of nephrotoxic drugs in their contribution to ARF, these drugs continue to have an ongoing aetiological role. Potentially nephrotoxic drugs include non-steroidal anti-inflammatory drugs, radiocontrast agents, antimicrobial and anaesthetic agents. Endogenous compounds such as myoglobin and haemoglobin may furthermore cause toxic nephropathy. Tubular injury initiated by toxins often results from a combination of acute renal vasoconstriction and direct cellular toxicity due to intracellular accumulation of the toxin, or, alternatively, may be mediated immunologically in case of interstitial nephritis. Patients with reduced renal functional reserve, cardiovascular co-morbidity, diabetes mellitus, and advanced age are at increased risk. Awareness of the range of toxins on the one hand and simple measures such as adequate pre-hydration of the patient and drug monitoring on the other hand may be sufficient to avoid drug-induced ARF or minimize its clinical severity in susceptible patients.