Low-dose dopamine induces early recovery of recombinant interleukin-2--impaired renal function

The identification of dual protective agents against cisplatin-induced oto- and nephrotoxicity using the zebrafish model

Dose-limiting toxicities for cisplatin administration, including ototoxicity and nephrotoxicity, impact the clinical utility of this effective chemotherapy agent and lead to lifelong complications, particularly in pediatric cancer survivors. Using a two-pronged drug screen employing the zebrafish lateral line as an in vivo readout for ototoxicity and kidney cell-based nephrotoxicity assay, we screened 1280 compounds and identified 22 that were both oto- and nephroprotective. Of these, dopamine and L-mimosine, a plant-based amino acid active in the dopamine pathway, were further investigated. Dopamine and L-mimosine protected the hair cells in the zebrafish otic vesicle from cisplatin-induced damage and preserved zebrafish larval glomerular filtration. Importantly, these compounds did not abrogate the cytotoxic effects of cisplatin on human cancer cells. This study provides insights into the mechanisms underlying cisplatin-induced oto- and nephrotoxicity and compelling preclinical evidence for the potential utility of dopamine and L-mimosine in the safer administration of cisplatin.

Immunomodulators: interleukins, interferons, and IV immunoglobulin

The outstanding progress in immunology and the development of new technologies have resulted in the introduction of new immunotherapies, the so-called “immunomodulators”, for autoimmune diseases, inflammatory disorders, allograft rejection, and cancer. These immunomodulators comprise recombinant cytokines and specific blocking or depleting antibodies. Many of these therapies achieve their effect by stimulating the release of cytokines. The term cytokines includes interleukins (IL-), chemokines, growth factors, interferons (IFN), colony stimulating factors (CSF), and tumor necrosis factors (TNF). These molecules are involved in inflammation, cell proliferation and apoptosis, tissue injury and repair.

These new therapeutic tools can be associated with side effects among which nephrotoxicity. The most common immunomodulators associated with nephrotoxicity are described in Table 1. The nephrotoxic side effects of immunomodulators can be roughly divided into (ischemic) tubular necrosis, thrombotic microangiopathy, serum sickness, and autoimmune disorders.

Use of dopamine in acute renal failure: a meta-analysis

OBJECTIVE

To determine whether low-dose dopamine administration reduces the incidence or severity of acute renal failure, need for dialysis, or mortality in patients with critical illness.

DATA SOURCES AND STUDY SELECTION

We performed a MEDLINE search of literature published from 1966 to 2000 for studies addressing the use of dopamine in the prevention and/or treatment of renal dysfunction.

DATA EXTRACTION

Data were abstracted regarding design characteristics, population, intervention, and outcomes. Results of individual randomized clinical trials were pooled using a fixed effects model and a Mantel-Haenszel weighted chi-square analysis.

DATA SYNTHESIS

We identified a total of 58 studies (n = 2149). Of these, outcome data were reported in 24 studies (n = 1019) and 17 of these were randomized clinical trials (n = 854). Dopamine did not prevent mortality, (relative risk, 0.90 [0.44-1.83]; p =.92), onset of acute renal failure (relative risk, 0.81 [0.55-1.19]; p =.34), or need for dialysis, (relative risk, 0.83 [0.55-1.24]; p =.42). There was sufficient statistical power to exclude any large (>50%) effect of dopamine on the risk of acute renal failure or need for dialysis.

CONCLUSIONS

The use of low-dose dopamine for the treatment or prevention of acute renal failure cannot be justified on the basis of available evidence and should be eliminated from routine clinical use.

Low-dose "renal" dopamine

Low dose renal dopamine continues to be infused in patients at risk for renal dysfunction or as a therapy after acute renal failure has been established. This article reviews the impact of acute renal failure on patients and reviews the history and use of dopamine therapy for patients. A discussion of the rationale, positive and equivocal evidence, side effects, and possible clinical indications for low-dose renal dopamine therapy is included.

An evaluation of pharmacological strategies for the prevention and treatment of acute renal failure

Acute renal failure (ARF) occurs frequently in hospitalised patients, and is associated with significant morbidity and mortality. The most common and generalised forms of acute renal failure are pre-renal conditions and intra-renal acute tubular necrosis (ATN). Pre-renal ARF in its pure state should be entirely reversible by restoring renal perfusion, but in some cases ATN has already occurred. ATN remains a more vexing problem, and is seen most often with hypotension, perioperative or systemic inflammatory stresses, radiocontrast administration, and exposure to nephrotoxins. Among the available pharmacological options for prevention or treatment of ATN, there is a remarkable lack of definitive evidence supporting specific therapy in any setting. Although loop diuretics, mannitol, and dopamine are frequently used for prevention and/or treatment of ATN, clinical studies have failed to prove value. Other drugs with theoretical value, specifically atrial natriuretic peptide analogues, adenosine blockers, and calcium antagonists, have been insufficiently studied to recommend use. Other pharmacological options may arise in the future. Ensuring adequate intravascular fluid volume remains the only approach to managing ATN which can be considered relatively effective and safe. Given the abundant theoretical basis for the prevention and treatment of ATN with drugs, well conducted clinical studies with relevant outcome measures are clearly warranted.

Can the use of low-dose dopamine for treatment of acute renal failure be justified?

The use of dopamine for the prevention and treatment of acute renal failure is widespread. Its use is based on physiology suggesting selective renal vasodilation when it is infused at low dose. This article reviews the available data on the clinical use of dopamine. When used to prevent acute renal failure in high-risk treatments there is no evidence of benefit of dopamine but, given the low incidence of significant renal failure, the studies are underpowered. In treatment of acute renal failure, the quality of the data is poor. Only in one small randomised trial of moderate acute renal failure in patients with malaria was a clinically significant benefit of dopamine shown. The rest of the data, in the form of case series, showed either no benefit of dopamine or small benefits of little clinical significance. Again, these studies are of insufficient power for conclusions to be drawn as to the overall benefits and risks. We conclude that benefits of dopamine use cannot be ruled out by currently available data but its use cannot be advised until trials examining clinically important endpoints in large numbers of patients have been performed.

The use of diuretics and dopamine in acute renal failure: a systematic review of the evidence

OBJECTIVE: To evaluate the impact of diuretics and dopamine for both the prevention and treatment of renal dysfunction in the acute care setting. STUDY IDENTIFICATION AND SELECTION: Studies were identified via MEDLINE, and through bibliographies of primary and review articles. Articles were then screened by the author for studies addressing the use of diuretics or dopamine in the prevention and/or treatment of renal dysfunction. DATA ABSTRACTION AND LITERATURE APPRAISAL: From individual studies, data were abstracted regarding design features, population, intervention and outcomes. Studies were graded by levels according to their design. RESULTS: A total of 10 studies using diuretics and 30 involving dopamine were identified. Level I evidence exists against the use of diuretics for radiocontrast-induced acute tubular necrosis, and loop diuretics given after vascular surgery. There is level II evidence that diuretics do not improve outcome in patients with established acute renal failure. Level II evidence also exists against the use of dopamine in the prevention of acute tubular necrosis in multiple subsets of patients. CONCLUSIONS: Routine use of diuretics or dopamine for the prevention of acute renal failure cannot be justified on the basis of available evidence.