Amiloride prevents amphotericin B related hypokalaemia in neutropenic patients

The Use of Amiloride and Sodium-Glucose Cotransporter 2 Inhibitors in Cisplatin-Induced Hypomagnesemia: A Case Report and Review of the Literature

Cisplatin, a chemotherapy agent widely used since its FDA approval in 1978 for testicular cancer, is associated with nephrotoxicity and hypomagnesemia. Magnesium supplementation is not only a treatment for hypomagnesemia but also a well-established agent in preventing cisplatin-induced nephrotoxicity (CIN). Considering the challenges associated with intravenous magnesium use and even with the supplementation of oral forms, there is a need for drugs that effectively reduce urinary magnesium excretion. Amiloride and sodium-glucose cotransporter 2 inhibitors (SGLT2 inhibitors) have emerged as potential candidates. Amiloride is a well-known potassium-sparing diuretic that also has a hypomagnesemia effect seen in preclinical data. SGLT2 inhibitors are a drug class initially used in diabetes that was also observed to have positive effects on cardiovascular mortality, diabetic kidney disease, and hypomagnesemia. SGLT2 inhibitors were found to reduce hypomagnesemia in a meta-analysis study of 18 trials. However, these trials were not specifically designed for the evaluation of hypomagnesemia, and their current use in hypomagnesemia is considered off-label.

Comparison of intravenous sodium bicarbonate and sodium chloride combination versus intravenous sodium chloride hydration alone in reducing amphotericin B nephrotoxicity: a randomized clinical trial

Background and purpose:

The most important adverse reaction of amphotericin B (AmB) is nephrotoxicity. The aim of this study was to assess the potential effectiveness of intravenous saline + sodium bicarbonate versus intravenous sodium chloride hydration in preventing or attenuating AmB nephrotoxicity.

Experimental approach:

A randomized, non-placebo-controlled, single-blinded clinical trial was conducted in two adult hematology-oncology wards of Namazi hospital. Eligible patients were randomly assigned into either the normal saline or normal saline + sodium bicarbonate groups by the ratio of 1:2. In the normal saline group, 1000 mL of sodium chloride 0.9% (154 meq sodium) was given intravenously as two equal 500 mL volumes before and during the infusion of AmB. Patients in the saline + sodium bicarbonate group received 500 mL sodium chloride 0.9% (72 meq sodium) before and 500 mL isotonic sodium bicarbonate (72 meq sodium) intravenously during AmB infusion.

Findings/Results:

The rate of AmB nephrotoxicity was comparable between normal saline and sodium bicarbonate groups (54.2% and 41.6%, respectively; P = 0.3). This difference did not reach the level of statistical significance after considering AmB dose and duration of the treatment. The frequency of hypokalemia and hypomagnesemia did not differ significantly between the two groups even after adjusting the results according to AmB dose and treatment duration.

Conclusion and implications:

The results of the current preliminary clinical trial suggested that the combination of sodium bicarbonate and normal saline compared to normal saline alone appears to have no superiority in preventing or attenuating different studied aspects of AmB nephrotoxicity in patients with hematological malignancies.

Consensus guidelines for optimising antifungal drug delivery and monitoring to avoid toxicity and improve outcomes in patients with haematological malignancy, 2014

Antifungal agents may be associated with significant toxicity or drug interactions leading to sub-therapeutic antifungal drug concentrations and poorer clinical outcomes for patients with haematological malignancy. These risks may be minimised by clinical assessment, laboratory monitoring, avoidance of particular drug combinations and dose modification. Specific measures, such as the optimal timing of oral drug administration in relation to meals, use of pre-hydration and electrolyte supplementation may also be required. Therapeutic drug monitoring (TDM) of antifungal agents is warranted, especially where non-compliance, non-linear pharmacokinetics, inadequate absorption, a narrow therapeutic window, suspected drug interaction or unexpected toxicity are encountered. Recommended indications for voriconazole and posaconazole TDM in the clinical management of haematology patients are provided. With emerging knowledge regarding the impact of pharmacogenomics upon metabolism of azole agents (particularly voriconazole), potential applications of pharmacogenomic evaluation to clinical practice are proposed.

N-acetyl cysteine in prevention of amphotericin- induced electrolytes imbalances: a randomized, double-blinded, placebo-controlled, clinical trial

PURPOSE

The aim of this study was to evaluate the effectiveness of oral n-acetyl cysteine, as a potential nephroprotective agent, in preventing and/or attenuating amphotericin B-induced electrolytes imbalances.

METHODS

During a one year period, patients were to receive conventional amphotericin b for any indication for at least one week and were randomly allocated to receive either placebo or 600 mg oral n-acetyl cysteine twice daily during the treatment course of amphotericin b. Demographic and clinical data of the study population were gathered. Different aspects of amphotericin b nephrotoxicity including decrease of glomerular filtration rate, hypokalemia, hypomagnesemia, renal magnesium and potassium wasting were assessed. Each patient was monitored for any adverse reaction to n-acetyl cysteine. Sixteen and 14 patients in the n-acetyl cysteine and placebo groups completed the study, 3incidences of hypokalemia (75 % versus 70 %; P = 0.724) and hypomagnesemia (30 % versus 20 %; P = 0.468) did not differ significantly between placebo and NAC groups, respectively. Although the rate of AmB nephrotoxicity was higher in the placebo than in the NAC group (60 % versus 40 %), this difference was not statistically significant (P = 0.209) even after adjusting for probable associated factors of amphotericin b nephrotoxicity (P = 0.206). The incidence as well as time of onset of electrolyte abnormalities also did not differ significantly between placebo and n-acetyl cysteine groups. About 44 % of n-acetyl cysteine recipients experienced new onset nausea and a mild unpleasant taste during the study.

CONCLUSION

Oral n-acetyl cysteine during the amphotericin B treatment course was not significantly effective in preventing or mitigating different features of its nephrotoxicity including decrease of glomerular filtration rate, hypokalemia, hypomagnesemia, and renal potassium as well as magnesium wasting.

Role of diuretics and lipid formulations in the prevention of amphotericin B-induced nephrotoxicity

PURPOSE

To collect available clinical data to define the role of diuretics and lipid formulations in the prevention of amphotericin B (AmB)-induced nephrotoxicity (AIN) in human populations.

METHOD

A literature search was performed in the following databases: Scopus, Medline, Embase, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews.

RESULTS AND CONCLUSION

Co-administration of mannitol failed to show any clinically significant benefit in preventing AIN. Potassium-sparing diuretics, such as amiloride and spironolactone, have been shown to have beneficial effects as an alternative or adjunct to oral/parenteral potassium supplements in preventing hypokalemia due to AmB. Lipid-based formulations of AmB are clinically effective and safe in preventing AIN. However, due to their high cost and limited accessibility, these formulations are generally used as second-line antifungal therapy in cases of conventional AmB refractoriness and/or intolerance or pre-existing renal dysfunction. The potential effects of other nephroprotective agents, such as N-acetylcysteine, AIN merit further considerations and investigations.

Electrolyte disturbances and acute kidney injury in patients with cancer

The interrelation between kidney disease and cancer is complex and reciprocal. Among the most frequent cancer-associated kidney diseases are the electrolyte and acid-base disturbances, which occur frequently and often are associated with an ominous prognosis, and acute kidney injury. Tumor lysis syndrome is a potentially life-threatening condition that frequently occurs in patients with a high tumor burden and high cellular turnover after cytotoxic therapy (including steroids in steroid-sensitive hematologic malignancies). Electrolyte and acid-base disturbances are the consequence of neoplastic spread, anticancer treatment, or, more rarely, paraneoplastic phenomena of all types of tumors. This article reviews hyponatremia and hypernatremia, hypokalemia and hyperkalemia, hypomagnesemia, hypercalcemia and hypocalcemia, hypophosphatemia, and the most important disturbances in acid-base balance in cancer patients. Acute kidney injury (AKI) is a frequent occurrence in cancer patients and has the potential to substantially alter the outcome of patients with cancer and jeopardize their chances of receiving optimal cancer treatment and a potential cure. As in many other circumstances, the etiology of AKI in cancer patients is multifactorial. Initiation and/or continuation of dialysis in the AKI cancer patient should be based on the general clinical condition and overall life expectancy and the personal patient expectations on quality of life after eventual recovery.

Antifungal chemotherapeutics

This review addresses trends in outcome and risk factors for invasive fungal infections, current antifungal agents and new therapeutic strategies. Current prospects for new therapies rest upon caspofungin, the first of a new class of antifungal molecules, the echinocandins, and new extended-spectrum azoles, voriconazole, posaconazole and ravuconazole. Approval by the Food and Drug Administration of the USA and the European Medicine Agency was given in 2001-2002 to voriconazole and caspofungin. Voriconazole clearly demonstrated a decrease in mortality in invasive aspergillosis and fusariosis fungal infections.

A new era of antifungal therapy

Invasive fungal infections pose major management problems for clinicians caring for hematopoietic cell transplant patients. Two major fungal genera, Candida and Aspergillus, account for most fungal infections. Rates of systemic Candida infection range from 15% to 25%, mostly in the pre-engraftment period. Prophylaxis by fluconazole has dramatically reduced the frequency of early Candida infections. Caspofungin has recently been shown to offer an excellent alternative to amphotericin B (with less toxicity) or fluconazole (with a broader spectrum) for therapy of systemic Candida infections. Aspergillus infections occur in 15% to 20% of allogeneic hematopoietic cell transplant patients, most frequently in the post-engraftment period; they are associated with a severe diminution of cell-mediated immune responses by graft-versus-host disease and prolonged corticosteroid use. Voriconazole, a recently introduced broad-spectrum azole, has excellent activity against Aspergillus and is generally well tolerated. Voriconazole currently offers the best prospect for success and tolerance as a first-line treatment for aspergillosis. Second-line therapies include lipid formulations of amphotericin B, caspofungin, or intravenous itraconazole. Unfortunately, early initiation of therapy for aspergillosis is frequently not possible because of inaccurate diagnostics. One new diagnostic, the galactomannan assay, has recently been approved, and others are in development; these offer promise for earlier diagnosis without the need for invasive procedures. It is hoped that these new therapies and new diagnostics will usher in a new era of antifungal therapy.

Correlates of acute renal failure in patients receiving parenteral amphotericin B

BACKGROUND

While parenteral amphotericin B is an effective therapy for serious fungal infections, it frequently causes acute renal failure (ARF). This study identified correlates of ARF in amphotericin B therapy and used them to develop clinical prediction rules.

METHODS

All 643 inpatients receiving parenteral amphotericin B therapy at one tertiary care hospital were included. Data regarding correlates were obtained both electronically and from manual chart review in a subsample of 231 patients. ARF was defined as a 50% increase in the baseline creatinine with a peak > or =2.0 mg/dL.

RESULTS

Among 643 episodes, ARF developed in 175 (27%). In the larger group, the only independent correlate of ARF was male gender (OR = 2.2, 95% CI, 1.5 to 3.3). In the subsample (N = 231), independent correlates of ARF were maximum daily amphotericin dosage, location at the time of initiation of amphotericin therapy, and concomitant use of cyclosporine. These data were used to develop two clinical prediction rules. A rule using only data available at initiation of therapy stratified patients into groups with probability of ARF ranging from 15 to 54%, while a rule including data available during therapy (maximum daily dose) stratified patients into groups with probability of ARF ranging from 4 to 80%.

CONCLUSIONS

Acute renal failure occurred in a quarter of the patients. Correlates of ARF at the beginning and during the course of amphotericin therapy were identified and then combined to allow stratification according to ARF risk. These data also provide evidence for guidelines for the selection of patients for alternative therapies.

Mortality and costs of acute renal failure associated with amphotericin B therapy

To assess the mortality and resource utilization that results from acute renal failure associated with amphotericin B therapy, 707 adult admissions in which parenteral amphotericin B therapy was given were studied at a tertiary-care hospital. Main outcome measures were mortality, length of stay, and costs; we controlled for potential confounders, including age, sex, insurance status, baseline creatinine level, length of stay before beginning amphotericin B therapy, and severity of illness. Among 707 admissions, there were 212 episodes (30%) of acute renal failure. When renal failure developed, the mortality rate was much higher: 54% versus 16% (adjusted odds of death, 6.6). When acute renal failure occurred, the mean adjusted increase in length of stay was 8.2 days, and the adjusted total cost was $29,823. Although residual confounding exists despite adjustment, the increases in resource utilization that we found are large and the associated mortality is high when acute renal failure occurs following amphotericin B therapy.

Amiloride for the prevention of amphotericin B-induced hypokalemia and hypomagnesemia

OBJECTIVE

To review the published clinical data assessing the role of amiloride in the prevention of amphotericin B (AmB)induced electrolyte disorders.

DATA SOURCES

A MEDLINE search (January 1966-April 1999) of English-language literature pertaining to AmB, amiloride, potassium, and magnesium was performed. Tertiary sources were also used.

DATA EXTRACTION

In vivo and in vitro human and animal data and case reports were included due to the lack of published clinical trials.

DATA SYNTHESIS

AmB administration can result in severe hypokalemia and hypomagnesemia requiring chronic supplementation. In one prospective, controlled study of hypokalemia with AmB administration, patients receiving concomitant amiloride had significantly greater potassium concentrations (p < 0.01) and required significantly less potassium supplementation (p < 0.001). Amiloride may also reduce the amount of magnesium supplementation required by sparing elimination through the kidneys.

CONCLUSIONS

Amiloride may be considered for the prevention of AmB-induced hypokalemia and hypomagnesemia, especially in patients at high risk for complications resulting from these electrolyte disorders. Further studies are needed to assess concomitant use of other potassium-sparing diuretics and AmB.

Adverse drug reactions to systemic antifungals. Prevention and management

Systemic administration of antifungal agents for invasive mycoses has dramatically increased over the past 10 years in many fields of medicine. The increase has been due both to an increasing immune compromised population and to potent antibacterial agents which allow these fungi to invade tissue. It is apparent that our understanding of the use of both the old and new antifungal agents has significantly increased in the last few years. In this review, we attempt to document our extensive knowledge of the adverse effects of the polyenes, flucytosine, griseofulvin and azoles when given systemically for treatment. Interwoven in this documentation of the adverse reactions to these agents is the attempt to help clinicians potentially avoid some of these adverse effects and if they do occur, to be able to identify and successfully manage them.

The pharmacology and therapeutics of diuretics in the pediatric patient

Selection of appropriate diuretic therapy in children is hampered by a lack of age-specific pharmacokinetic and pharmacodynamic data, especially in premature neonates. Well-designed clinical trials in neonates, infants, and younger children are necessary prerequisites to safer and more efficacious diuretic therapy.