Rapid infusion of amphotericin B: is it safe, effective, and wise?

How urgent is the need for new antifungals?

Introduction: Invasive fungal infection carries a high morbidity, mortality and economic cost. In recent times, a rising incidence of fungal infection and antifungal resistance is occurring which has prompted the development of novel antifungal agents.Areas covered:In this perspective, the authors describe the current status of registered antifungals and their limitations in the treatment of invasive fungal infection. They also go on to describe the new antifungal agents that are in the clinical stage of development and how they might be best utilized in patient care in the future.Expert opinion: The antifungal drug development pipeline has responded to a growing need for new agents to effectively treat fungal disease without concomitant toxicity or issues with drug tolerance. Olorofim (F901318), ibrexafungerp (SCY-078), fosmanogepix (APX001), rezafungin (CD101), oteseconazole (VT-1161), encochleated amphotericin B (MAT2203), nikkomycin Z (NikZ) and ATI-2307 are all in the clinical stage of development and offer great promise in offering clinicians better agents to treat these difficult infections.

Placental Trophoblast-Inspired Lipid Bilayers for Cell-Free Investigation of Molecular Interactions

The placenta plays a key role in regulating the maternal-fetal transport but it is a difficult organ to study due to a lack of existing in vitro models. Lipid bilayers inspired by the placenta can provide a facile new in vitro tool with promise for screening molecular transport across this important organ. Here we developed lipid bilayers that mimic the composition of human placental trophoblast cells at different times during the course of pregnancy. Mass spectrometry identified five major lipid classes (phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, and sphingomyelin) present at varying concentrations in trophoblasts representative of the first and third trimesters and full-term placenta. We successfully developed supported and suspended lipid bilayers mimicking these trophoblast lipid compositions and then demonstrated the utility of these synthetic placenta models for investigating molecular interactions. Specifically, we investigated the interactions with di(2-ethylhexyl) phthalate (DEHP), a common plasticizer and environmental toxicant, and amphotericin B, a common yet toxic, antifungal therapeutic. Overall, we observed that DEHP adsorbs and potentially embeds itself within all placental lipid bilayers, with varying levels of interaction. For both amphotericin B and a liposomal formulation of amphotericin B, AmBisome, we noted lower levels of permeation in transport studies with bilayers and trophoblast cells compared with DEHP, likely driven by differences in size. AmBisome interacted less with both the supported and suspended placental lipid bilayers in comparison to amphotericin B, suggesting that drug delivery carriers can vary the impact of a pharmaceutical agent on these lipid structures. We found that the apparent permeability observed in suspended bilayers was approximately an order of magnitude less than those observed for trophoblast monolayers, which is typical of lipid bilayers. Ultimately, these placenta mimetic lipid bilayers can serve as a platform for the rapid initial screening of molecular interactions with the maternal-fetal interface to better inform future testing.

Pulmonary reactions during treatment with amphotericin B: review of published cases and guidelines for management

Acute respiratory events occasionally have been observed during the infusion of amphotericin B. Herein we analyze the 21 cases that have been reported, including a fatal reaction observed by us. Some useful guidelines are provided that likely will allow treatment to be continued safely for patients who have experienced such reactions.

Amphotericin B-associated hypertension

OBJECTIVE

To report two cases of hypertension related to amphotericin B infusion.

CASE SUMMARY

A 63-year-old woman with Candida albicans bacteremia and an 84-year-old man with Aspergillus fumigatus pneumonia developed hypertension within minutes of amphotericin B administration. Both patients' blood pressure returned to baseline soon after the infusion of amphotericin B was stopped. Neither patient was rechallenged.

DISCUSSION

A causal relationship may exist between the administration of amphotericin B and these hypertensive episodes. Blood pressure in both patients normalized without treatment on discontinuation of the infusion. The mechanism of amphotericin B-associated hypertension is unclear but could include vasoconstricting properties of the drug or the administration of intravenous NaCl 0.9% prior to amphotericin B infusion. We recommend that intravenous NaCl 0.9% be administered following amphotericin B infusion and that the infusion be stopped if hypertensive episodes arise.

CONCLUSIONS

Both acute hypertension and hypotension can occur in patients receiving amphotericin B for systemic fungal infections.

Rapid infusion of amphotericin B in dextrose

OBJECTIVE

To review the data examining the use of rapid infusion of amphotericin B in dextrose infusions.

DATA SOURCES

A MEDLINE search of the English-language literature and review of pertinent references' bibliographies was used to identify articles evaluating the effect of amphotericin B infusion rates on the incidence of adverse reactions.

STUDY SELECTION AND DATA EXTRACTION

Controlled and uncontrolled studies involving humans are reviewed; emphasis is placed on recent comparative trials. Pertinent information, as judged by the authors, was selected for discussion.

DATA SYNTHESIS

Amphotericin B, a polyene antifungal agent with significant toxicity, remains the agent of choice for many serious fungal infections. The potential benefits of rapid administration of amphotericin B in reducing the incidence and/or severity of adverse reactions were noted soon after its introduction. Recent studies have examined the tolerability of rapid (0.75-1 h) amphotericin B infusions. Results of studies assessing the tolerability of rapid amphotericin B infusions suggest that tolerance to infusion-related reactions develops during therapy. Comparative trials have obtained variable results. The comparative trials supporting rapid amphotericin B infusion have generally used crossover designs, enrolled small numbers of patients, and excluded patients with significant renal or cardiovascular dysfunction.

CONCLUSIONS

Rapid amphotericin B infusions should be avoided during initiation of therapy when infusion-related reactions tend to be most problematic, and in patients with cardiovascular disease, renal dysfunction, and potassium disorders because of the potential risk for cardiac arrhythmias. The literature currently available is conflicting and insufficient to support the routine use of rapid amphotericin B infusion.