Randomized, double-blind trial of 1- versus 4-hour amphotericin B infusion durations

Amphotericin-Associated Infusion-Related Reactions: A Narrative Review of Pre-Medications

PURPOSE

Amphotericin B has been reported to cause infusion-related adverse effects (IRAEs). To prevent IRAEs, pre-medications may be administered prior to the administration of amphotericin B. The effects of different formulations of amphotericin B (amphotericin B deoxycholate and lipid formulations), duration of infusion, and utility of pre-medications in preventing IRAEs are reviewed.

METHODS

PubMed, Ovid Medline, Embase, Web of Science, the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, and the Scopus databases were searched with the following search terms: pre-medication, amphotericin B, and its related compounds. Upon review, a total of 39 publications were considered for inclusion.

FINDINGS

In vitro and in vivo studies have reported that amphotericin B deoxycholate stimulates pro-inflammatory cytokine genes causing IRAEs. Nonetheless, the clinical literature has reported that IRAEs occur among patients who received pre-medications. In comparison to amphotericin B deoxycholate, lipid-based formulations of amphotericin may result in a lower or similar risk for IRAEs.

IMPLICATIONS

The routine use of pre-medications to prevent IRAEs after the administration of amphotericin B (amphotericin B deoxycholate or lipid formulations) would not be warranted.

Continuously infused amphotericin B deoxycholate for primary treatment of invasive fungal disease in acute myeloid leukaemia

Continuous administration of amphotericin B deoxycholate over 24 hours (24 h-D-AmB) is better tolerated than rapid infusions. However, toxicity and outcome have not been assessed in a homogenous patient population with acute myeloid leukaemia (AML). We retrospectively analysed renal function and outcome in all adult patients with AML undergoing intensive chemotherapy between 2007 and 2012 at our institution. We compared a patient group with exposure to 24 h-D-AmB to a patient group without exposure to 24 h-D-AmB. One hundred and eighty-one consecutive patients were analysed, 133 (73.5%) received at least 1 dose of 24 h-D-AmB, and 48 (26.5%) did not. Reasons for 24 h-D-AmB initiation were invasive fungal disease (IFD) in 63.5% and empirical treatment for febrile neutropenia in 36.5% of the cases. Most patients with IFD received an oral triazole drug at hospital discharge. Baseline characteristics were well matched. Amphotericin B deoxycholate over 24 hours was given for a median 7 days (interquartile range 3-13). Peak creatinine concentration was higher in the 24 h-D-AmB-group (104.5 vs. 76 μmol/L, P < .001) but normalized within 1 month after therapy (65.5 vs. 65 μmol/L, P = .979). In neither of the 2 groups, end-stage renal disease occurred. There was no difference in 60-day survival (90% vs. 90%) and 2-year survival (58% vs. 58%). Invasive fungal disease partial response or better was observed in 68% of the patients. We conclude that antifungal therapy with continuously infused amphotericin B deoxycholate is safe in patients with AML. An antiinfective strategy based on 24 h-D-AmB in first line followed by an oral triazole compound represents an economically attractive treatment option.

continuous versus conventional infusion of amphotericin B deoxycholate: a meta-analysis

Background

Treatment with Amphotericin B (AmB) deoxycholate, which is still used widely, particularly in low-resource countries, has been challenged due to nephrotoxicity. We sought to study whether continuous infusion of AmB deoxycholate reduces nephrotoxicity retaining, however, the effectiveness of the drug.

Methods

PubMed and Scopus databases were systematically searched to identify studies comparing the outcomes of patients receiving 24-h infusion of AmB (“continuous group”) and those receiving 2–6-h infusion of AmB (“conventional group”). Nephrotoxicity and all-cause mortality were the primary outcomes of the review, while treatment failure was the secondary outcome.

Results

Five studies met the inclusion criteria; one randomized controlled trial, two prospective cohort studies, and two retrospective cohort studies. The majority of patients were neutropenic with an underlying hematologic malignancy. All 5 studies (392 patients) provided data regarding the development of nephrotoxicity. A non-significant trend towards lower nephrotoxicity was observed for patients receiving continuous infusion of AmB compared with those receiving conventional infusion [RR = 0.61 (95% CI 0.36, 1.02)]. Four studies (365 patients) provided data regarding mortality; no relevant difference was detected between patients receiving continuous and those receiving conventional infusion of AmB [RR = 0.81 (95% CI 0.36, 1.83)]. Data on treatment failure of the two methods of administration was insufficient for meaningful conclusions.

Conclusion

The available evidence from mainly non-randomized studies suggests that continuous infusion of AmB deoxycholate might offer an advantage over the conventional infusion regarding the development of nephrotoxicity, without compromising patient survival. Further randomized studies are needed to investigate this issue.

New agents for the treatment of systemic fungal infections – current status

Systemic antifungal chemotherapy is enjoying its most dynamic era. More antifungal agents are under development than ever before, including agents in entirely new classes. Major goals of current investigations are to identify compounds with a wide spectrum of activity, minimal toxicity and a high degree of target specificity. The antifungal drugs in development include new azoles {voriconazole, posaconazole (formerly SCH-56592), ravuconazole (formerly BMS-207147)}, lipid formulations of amphotericin B, a lipid formulation of nystatin, echinocandins {anidulafungin (formerly, LY-303366, VER-002), caspofungin (formerly MK-991), micafungin (formerly FK-463)}, antifungal peptides other than echinocandins, and sordarin derivatives. This discussion reviews the currently available antifungal agents and summarises the developmental issues that surround these new systemic antifungal drugs.

Continuous and 4 h infusion of amphotericin B: a comparative study involving high-risk haematology patients

OBJECTIVES

To assess whether a continuous infusion of amphotericin B (CI-AmB) is less nephrotoxic than a 4 h infusion in haematology patients with fever and neutropenia, including bone-marrow transplant recipients. Efficacy was assessed as a secondary end-point.

PATIENTS AND METHODS

We conducted a retrospective cohort study over a 2 year period. A total of 1073 haematology admissions were reviewed (98.3% complete) and 81 admissions were eligible for study entry; 39 received CI-AmB and 42 a 4 h infusion of AmB.

RESULTS

Renal impairment occurred significantly less frequently with CI-AmB compared with a 4 h infusion of AmB [10% versus 45%, respectively, odds ratio (OR) 0.14; 95% confidence interval (CI) 0.04-0.5, P < 0.001]. The difference was maintained among allogeneic transplant recipients (P = 0.007) and patients receiving concurrent nephrotoxic drugs (P < 0.001). An AmB infusion rate of <0.08 mg/kg/h was associated with a significant reduction in renal impairment (P < 0.001). A difference in survival was observed between the continuous and 4 h infusion of AmB (95% versus 79%, respectively, OR 5.1; 95% CI 1.02-25.1, P = 0.03).

CONCLUSIONS

CI-AmB appears to be significantly less nephrotoxic than 4 h infusion AmB in haematology patients with fever and neutropenia--including high-risk bone-marrow transplant recipients--without increasing mortality. An AmB infusion rate of <0.08 mg/kg/h appears to be a safe threshold, associated with reduced renal impairment.

Triad of acute infusion-related reactions associated with liposomal amphotericin B: analysis of clinical and epidemiological characteristics

We investigated the clinical characteristics and treatment of patients with a distinctive triad of acute infusion-related reactions (AIRRs) to liposomal amphotericin B (L-AMB) via single-center and multicenter analyses. AIRRs occurred alone or in combination within 1 of 3 symptom complexes: (1) chest pain, dyspnea, and hypoxia; (2) severe abdomen, flank, or leg pain; and (3) flushing and urticaria. The frequency of AIRRs in the single-center analysis increased over time. Most AIRRs (86%) occurred within the first 5 min of infusion. All patients experienced rapid resolution of symptoms after intravenous diphenhydramine was administered. The multicenter analysis demonstrated a mean overall frequency of 20% (range, 0%-100%) of AIRRs among 64 centers. A triad of severe AIRRs to L-AMB may occur in some centers; most of these reactions may be effectively managed by diphenhydramine administration and interruption of L-AMB infusion.

Pharmacotherapy of Candida bloodstream infections: new treatment options, new era

Evolving medical practices and the widespread use of fluconazole have clearly affected the spectrum of invasive mycoses now encountered by clinicians. The proportion of infections due to azole-resistant Candida species and invasive moulds has increased steadily over the last decade, creating a need for broad-spectrum antifungal agents with safety profiles similar to fluconazole. Efforts to address this need have lead to the reformulation of older, broad-spectrum antifungals and the development of new agents with enhanced activity against non-C. albicans and Aspergillus species. This review highlights pharmacodynamic, pharmacokinetic, safety and cost considerations for current and emerging antifungal therapies to be used in the treatment of bloodstream candidiasis.

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.

Systemic antifungal agents

Anti-fungal agents are classified under two major headings, systematic and topical agents. Only systematic anti-fungal agents will be discussed in this chapter. Since the discovery in 1955, amphotericin B has been the cornerstone of anti-fungal treatment. It is active against most species of fungi. However, Candida lusitaniae, Pseudallescheria boydii, and fusarium spp have primary resistance to amphotericin B. Recently, new liposomal preparations of amphotericin B have been developed. They are less nephrotoxic. The azole family of anti-fungal includes two broad classes: the imidazoles (clotrimazote, ketoconazote, miconazole) and the triazoles (flucouazole and itracouazole). Imidazoles are still widely used for the treatment of superficial mycoses and vaginal candidiasis. The systematic triazoles are more slowly metabolized and have less effect on human synthesis than imidazoles, hence they are preferred for systemic therapy. Flucytosine is a fluorinated pyrimidine. Clinically, the principal use of flucytosine is as adjunctive therapy with amphotericin B in the treatment of candidial or cryptococcal diseases, Griseofuluin is derived from penicillium. It is fungistatic in vitro for species of dermatophytes. It is useful for the treatment of tinea capitis and tinea unginum.

Comparison of effects of amphotericin B deoxycholate infused over 4 or 24 hours: randomised controlled trial

OBJECTIVE

To test the hypothesis that amphotericin B deoxycholate is less toxic when given by continuous infusion than by conventional rapid infusion.

DESIGN

Randomised, controlled, non-blinded, single centre study.

SETTING

University hospital providing tertiary clinical care.

PATIENTS

80 mostly neutropenic patients with refractory fever and suspected or proved invasive fungal infections.

INTERVENTION

Patients were randomised to receive 0.97 mg/kg amphotericin B by continuous infusion over 24 hours or 0.95 mg/kg by rapid infusion over four hours.

MAIN OUTCOME MEASURES

Patients were evaluated for side effects related to infusion, nephrotoxicity, and mortality up to three months after treatment. Analysis was on an intention to treat basis.

RESULTS

Patients in the continuous infusion group had fewer side effects and significantly reduced nephrotoxicity than those in the rapid infusion group. Overall mortality was higher during treatment and after three months' follow up in the rapid infusion than in the continuous infusion group.

CONCLUSION

Continuous infusions of amphotericin B reduce nephrotoxicity and side effects related to infusion without increasing mortality.

Lipid-based amphotericin B for the treatment of fungal infections

The frequency of life-threatening fungal infections has increased dramatically over the past few decades. For more than 30 years amphotericin B has been the standard treatment for systemic and deep-seated fungal infections, primarily because of its broad spectrum of activity. Its usefulness is limited by a relatively high frequency of significant adverse events including infusion-related reactions and nephrotoxicity. In an effort to overcome these side effects, a number of lipid-based formulations were developed, each with its own composition and pharmacokinetic behavior. The clinical significance of these differences is unknown. Available clinical data suggest the formulations have a reduced propensity for causing nephrotoxicity. However, considering limited efficacy data, they should be reserved as second-line therapy for patients who cannot tolerate or fail an adequate trial of conventional amphotericin B or cannot benefit from other antifungal agents.

Antifungal agents. Part I. Amphotericin B preparations and flucytosine

Traditionally, amphotericin B has been the cornerstone of antifungal treatment. Toxicity, however, is a major dose-limiting factor of amphotericin B deoxycholate. Nevertheless, it continues to have a major role in the treatment of deep-seated mycotic infections. Recently, less nephrotic lipid formulations, including amphotericin B lipid complex, amphotericin B cholesteryl sulfate, and liposomal amphotericin B, have been introduced. The pharmacologic properties, main indications, recommended dosages, related costs, and adverse effects of these various preparations are summarized in this review. Orally administered flucytosine is useful in certain infections, particularly cryptococcal meningitis, but it should be used with caution in patients with renal insufficiency.

Amphotericin B in lipid emulsion: stability, compatibility, and in vitro antifungal activity

Newer formulations of amphotericin B (AmB) complexed with liposomes or lipid suspensions have been developed. Preliminary studies have suggested that AmB in Intralipid (IL) may be as effective as, but less toxic than, conventional formulations of AmB, but few data are available regarding its stability, compatibility, or in vitro antifungal activity. A compatibility study was done to evaluate the effects of AmB concentrations in IL containing either 10 or 20% soybean oil. The effects of temperature, shaking, and AmB and IL concentrations on the stability of AmB-IL suspensions were analyzed by visual inspection and liquid chromatography. The in vitro antifungal activity of AmB-IL, compared to that of AmB alone against reference strains of Candida species was determined by using a broth macrodilution method in accordance with National Committee for Clinical Laboratory Standards guidelines (M27-T). Samples of AmB-IL which were lightly shaken retained more than 90% of the AmB concentration over 21 days when stored at either 4 or 23 degrees C. Varying the AmB concentration did not appear to affect the stability of AmB-IL. However, a precipitate was formed when mixtures with more than 30% lipid as a proportion of the total volume were centrifuged. AmB-IL and AmB alone had similar in vitro antifungal activities against reference strains of yeasts. Further pharmacologic and clinical studies with AmB-IL are warranted, although AmB should not be combined with IL in concentrations capable of producing a precipitate.

Amphotericin B lipid complex

OBJECTIVE

To evaluate the published data on the effectiveness and safety of amphotericin B lipid complex (ABLC) for the treatment of invasive mycosis and to evaluate data describing the pharmacologic properties and pharmacokinetic behavior of ABLC in both animals and humans.

DATA SOURCE

A MEDLINE search was conducted to identify literature published from 1965 to January 1997 for amphotericin B deoxycholate (DCAB) and ABLC. In addition, preliminary data published as abstracts and presented at national conferences on infectious disease and hematology within the last 6 years were also included in this review.

STUDY SELECTION

Both human and animal studies were reviewed. Animal and in vitro studies were selected to evaluate the pharmacologic and toxicologic properties of ABLC. For the evaluation of the efficacy, safety, and pharmacokinetic behavior of ABLC, large, well-controlled studies were reviewed. In addition, data from open-label and emergency use protocols were also included in the review.

DATA EXTRACTION

The study and analytical methods, results, and conclusions of the selected studies were evaluated. Pharmacokinetic data for both ABLC and DCAB that were derived from human subjects were also evaluated.

DATA SYNTHESIS

DCAB has been the cornerstone for the treatment of invasive mycosis, even though it has a narrow therapeutic index. Infusion-related toxicities (e.g., fever, chills, rigors) are likely due to DCAB stimulation of cytokine and prostaglandin synthesis. Conversely, nephrotoxicity, the primary non-infusion-related toxicity, likely results from the nonselective cytotoxic interaction between DCAB and cholesterol-containing mammalian cells. ABLC represents a new approach to improving the therapeutic index of DCAB. Mammalian cytotoxicity is attenuated by complexing amphotericin B to a mixture of phospholipids. This alters the affinity of amphotericin B and decreases its selective transfer from the complex to cholesterol-containing mammalian cells. Fungi also possess lipase, which improves the selective transfer from the complex to ergosterol-containing cell membranes. In humans, the lipid formulation increases the volume of distribution of amphotericin B. Thus, compared with DCAB, larger doses of ABLC can be administered for a longer duration with less nephrotoxicity. However, the prevalence of infusion-related toxicities associated with ABLC is similar to that of DCAB. Whether the alteration in distribution improves efficacy by improving tissue concentrations of amphotericin B has not been determined. The cost of this agent will limit its use.

CONCLUSIONS

ABLC has been shown to be at least as effective as DCAB, and it has been well tolerated in the clinical studies to date. Despite large dosages and extended courses of administration, there is little nephrotoxicity associated with its use. However, the cost of this agent will limit its use to the treatment of refractory mycosis or to cases where DCAB is contraindicated due to significant renal insufficiency.

Controlled pilot study of rapid amphotericin B infusions

This pilot study compared the toxicity of a one hour with a four hour amphotericin B infusion in children. There were more severe chills in the former group on the first day of infusion, and more hypotension in the latter group over the study duration.

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.

Amphotericin B infusion-related toxicity: comparison of two- and four-hour infusions

OBJECTIVE

To investigate the influence of infusion duration on infusion-related adverse effects (IRAEs) associated with prophylactic or treatment regimens of amphotericin B in patients with leukemia/bone marrow transplant (BMT).

DESIGN

Randomized, double-blind, 2-arm, complete crossover, prospective clinical trial.

SETTING

A university-affiliated tertiary care teaching hospital.

PARTICIPANTS

The study population consisted of 25 consecutive patients with leukemia/BMT who received 162 prophylactic regimen infusions and 169 treatment regimen infusions of amphotericin B via a central line. Prior to each infusion all patients received a parenteral IRAE prophylaxis regimen of diphenhydramine 25 mg and hydrocortisone 25 mg. No test doses or incremental amphotericin B doses were administered. Patients were monitored closely for IRAEs, which were documented by using a standardized data collection form.

MAIN OUTCOME MEASURES

The incidence and nature of IRAEs during a 6-hour monitoring period following the initiation of each infusion was measured. Patients served as their own controls. IRAEs were compared according to infusion duration and therapeutic indication.

RESULTS

Three hundred and thirty-one 2- and 4-hour amphotericin B infusions were administered. We found no difference between 2- and 4-hour infusions in the incidence and severity of IRAEs, including overall events (29% of 166 2-hour infusions vs. 25% of 165 4-hour infusions), chill scores (8% of 166 2-hour infusions vs. 7% of 165 4-hour infusions; highest score 7 vs. 6), nausea and vomiting (7% vs. 12%; highest score 4 in both groups), fever (3% vs. 2%), highest temperature increase (2.4 vs. 1.6 degrees C), systolic hypotension (6% vs. 2%), greatest decrease from baseline (40 vs. 62 mm Hg), diastolic hypotension (5% vs. 3%), and greatest decrease (30 vs. 28 mm Hg) (p > 0.05). Overall, IRAEs were less common in prophylactic treatment regimens (35 events [22%] in 162 infusions) than in treatment regimens (55 events [32%] in 169 infusions) (p < 0.05).

CONCLUSIONS

This study demonstrates that patients with leukemia/BMT without myocardial or renal dysfunction who receive hydrocortisone and diphenhydramine as premedications can tolerate 2-hour central line infusions of prophylactic or treatment regimens of amphotericin B as well as 4-hour infusions.

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.

Amphotericin B and its delivery by liposomal and lipid formulations

In recent years, new formulations of the original amphotericin B preparation (Fungizone) have been devised in order to overcome toxicity problems that frequently occur. These preparations represent an improved method of drug delivery, with an increased therapeutic index and a decrease in toxicity to mammalian cell membranes. The new formulations have different physico-chemical characteristics and differ in pharmacokinetic parameters. Their effects must be compared with conventional amphotericin B to ascertain potential roles in future antifungal therapy.

Risk of ventricular dysrhythmias during 1-hour infusions of amphotericin B in patients with preserved renal function

In order to assess the safety of 1-h infusions of amphotericin B (AMB), we prospectively monitored 213 1-h infusions of AMB (dose range, 0.27 to 0.89 mg/kg of body weight) in 27 patients with creatinine clearances of > 25 ml/min. Holter monitor tracings during 1-h infusions were compared with those during a 4-h baseline period of monitoring. There were no ventricular dysrhythmias during 1-h infusions of AMB that were not present during baseline monitoring. Nausea and/or rigors were noted for 32 (15%) infusions in six (22%) patients. No patient exhibited a temperature rise of > 1 degree C. We conclude that, in doses of up to 0.9 mg/kg, AMB does not appear to induce asymptomatic ventricular dysrhythmias when administered over 1 h to patients with creatinine clearances of > 25 ml/min.

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.

Antifungal agents used for deep-seated mycotic infections

The increased use of immunosuppressive regimens in organ transplantation and in the treatment of malignant lesions and the epidemic of acquired immunodeficiency syndrome (AIDS) are major reasons for the greater prevalence of fungal infections seen in clinical practice during the past decade. The traditional cornerstone of antifungal treatment, amphotericin B, continues to play a major role in deep-seated mycotic infections. The indications for intravenously administered miconazole have become limited. Orally administered flucytosine remains useful in certain infections, particularly cryptococcal meningitis. The new orally administered antifungal agents ketoconazole and fluconazole have been approved for clinical use and have supplanted amphotericin B in certain situations. Investigational antifungal agents, including liposomal amphotericin B, itraconazole, and saperconazole, hold promise for the future. Active investigation in the development of new antifungal agents is expected to continue.

Double-blind randomized study of the effect of infusion rates on toxicity of amphotericin B

Results of a double-blind randomized non-crossover study of rapid (45 min) versus slow (4 h) infusion of amphotericin B administered to 20 patients with proven or suspected fungal infection are reported. Toxicity was higher in the rapid infusion group than it was in the slow infusion group (mean total 7-day chill score, 173 +/- 276 versus 20 +/- 30 [P less than 0.01]; mean total 7-day dosage of meperidine required to abate rigors, 180 +/- 133 versus 58 +/- 78 mg [P less than 0.05]; and mean maximum total 7-day pulse rise, 225 +/- 64 versus 135 +/- 56 beats per min [P less than 0.02], respectively). When analyzed on a daily basis, the mean chill score, meperidine dosage, and pulse rise were also higher; and in addition, nausea and vomiting (5 of 11 patients who received a rapid infusion versus 0 of 9 patients who received a slow infusion [P less than 0.01]) appeared to be more common in those who received amphotericin B rapidly. The daily analysis approach proved that tolerance to these side effects developed with each subsequent infusion day, and by day 7 the incidence and severity were the same. This development of tolerance was significant for the mean chill score in the rapid infusion group (P less than 0.05) and for the proportion of patients with chills (P less than 0.005 for the slow infusion group; P less than 0.05 for the rapid infusion group). A decrease in creatinine clearance to greater than 51% of the baseline value was seen in two patients in each group. There were five deaths (four in the rapid infusion group, 1 in the slow infusion group) within 1 month, but none was clearly related to the amphotericin B infusion. The mean time to defervescence was similar for each group (10.8 +/- 4.1 days in the slow infusion group versus 9.9 +/- 5 days in the rapid infusion group). A rapid infusion regimen for amphotericin B cannot be recommended, at least during the first 5 to 7 days of treatment.