Abnormalities in liver enzymes during simultaneous therapy with itraconazole and amphotericin B in leukaemic patients

Conventional Amphotericin B Associated Nephrotoxicity in Patients With Hematologic Malignancies

Introduction: Amphotericin B (AmB-d) is one of the most effective therapeutic options against frequently life-threatening systemic fungal infections in patients with hematologic malignancies. However, significant adverse effects including nephrotoxicity associated with its use limit its more widespread use. The objectives of our study were to determine the incidence of AmB-d associated nephrotoxicity, to evaluate clinical and epidemiological characteristics of patients, and to support the notion that conventional amphotericin B remains a valid therapeutic option among hematologic patients with proper patient selection.

Materials and methods: A total of 110 patients with hematologic malignancies were admitted to our Hematology Unit between January 2014 and November 2017 who required anti-fungal therapy during intensive systemic chemotherapy. The incidence of AmB-d associated nephrotoxicity, side effect profile, time to nephrotoxicity, and clinical and epidemiological characteristics associated with treatment success were assessed retrospectively.

Results: Of the 110 patients receiving AmB-d, 70 (63.6%) were male and 40 (36.4%) were female. The mean age of participants was 44 years. The most common diagnosis was acute myeloid leukemia (n=53, 48.2%), and the most common chemotherapy protocol was 7 + 3 remission-induction (cytarabine 100 mg/m² days 1-7, Idarubicin 12 mg/m² days 1-3; n=24, 21.8%). In 56.4% of the patients, antifungal therapy was given empirically. In 40 patients (36.4%), nephrotoxicity was observed following antifungal treatment, and only four patients had stage 3 renal failure. The mean duration of time to nephrotoxicity from initiation of amphotericin B was four days (min: 2, max: 31). All patients were found to receive at least one additional potential nephrotoxic treatment during the antifungal treatment process. 

Conclusion: AmB-d is associated with a significant risk of nephrotoxicity. In most hematological patients, antifungal treatment is initiated empirically, and patients received prolonged courses of treatment. Therefore, it is plausible to initiate such treatment with AmB-d, when one considers the already high treatment costs in this patient group as well as the fact that AmB-d offers similar efficacy to antifungal agents at a lower cost. AmB-d may be recommended as a first-line agent in this patient group with the introduction of newer and more costly antifungal agents when needed, on the basis of the fact that these patients can be closely monitored in a hospital setting, reversible nature of nephrotoxicity upon discontinuation, and rare occurrence of severe renal failure requiring dialysis.

Oral antifungal drug interactions: a mechanistic approach to understanding their cause

Oral antifungal drugs are generally regarded as effective and safe when used according to their manufacturer's recommendation. However, when an oral antifungal agent is administered with certain interacting agents or classes of drugs, rare severe iatrogenic adverse experiences including death may occur. This article alerts and demystifies some of the clinically significant oral antifungal drug interactions by exploring their underlying pharmacological basis.

Amphotericin B and liver function

Amphotericin B is well established as a highly efficacious agent against systemic fungal infections in humans. The therapeutic potential of amphotericin B is limited due to its side effects. Although in clinical use for more than 35 years, impairment of liver function is not considered to be a typical adverse effect of amphotericin B. Experimental data suggest that the drug may interfere with the hepatic cytochrome P450 and may thus influence the metabolic capacity of the liver. A confirmation of such a finding in patients treated with amphotericin B would be of value. The incidence of severe acute or subacute hepatotoxicity in response to amphotericin B is very low. Frequently, in critically ill patients, it is not always clear whether liver abnormalities are caused by an antifungal agent or whether they are due to the critical condition of these patients. Nevertheless, there are experimental data suggesting that amphotericin B may influence the metabolic capacity of the liver. Accordingly, drug interactions during prolonged amphotericin B treatment seem possible. Careful monitoring of liver function in those patients receiving amphotericin B in combination with other drugs, which undergo hepatic metabolism or are potentially hepatotoxic, is recommended. In this review, the current understanding and knowledge of the clinical significance, detection, and possible pathogenesis of amphotericin-B-induced liver damage are presented. With respect to the current experimental data, the influence of the drug on the hepatic microsomal cytochrome P450 are also presented and discussed, as is the impact of several clinical studies using different amphotericin B formulas in humans.