Antifungal drug susceptibility testing. Working Party of the British Society for Antimicrobial chemotherapy

Amphotericin B versus fluconazole for controlling fungal infections in neutropenic cancer patients

BACKGROUND

Systemic fungal infection is considered to be an important cause of morbidity and mortality in cancer patients, particularly those with neutropenia. Antifungal drugs are often given prophylactically, or empirically to patients with persistent fever.

OBJECTIVES

To compare the effect of fluconazole and amphotericin B on morbidity and mortality in patients with cancer complicated by neutropenia.

SEARCH METHODS

We searched PubMed from 1966 to 7 July 2014 and the reference lists of identified articles.

SELECTION CRITERIA

Randomised clinical trials comparing fluconazole with amphotericin B.

DATA COLLECTION AND ANALYSIS

The two review authors independently assessed trial eligibility and risk of bias, and abstracted data.

MAIN RESULTS

Seventeen trials (3798 patients, 381 deaths) were included. In two large three-armed trials, results for amphotericin B were combined with results for nystatin in a 'polyene' group. Because nystatin is an ineffective drug in these circumstances, this approach creates a bias in favour of fluconazole. Furthermore, most patients were randomised to oral amphotericin B, which is poorly absorbed and poorly documented. There was overlap among the 'polyene' trials but we were unable to obtain any information from the trial authors or from Pfizer, the manufacturer of fluconazole, to clarify these issues. There were no significant differences in effect between fluconazole and amphotericin B, but the confidence intervals were wide. More patients dropped out of the study when they received amphotericin B, but as none of the trials were blinded decisions on premature interruption of therapy could have been biased. Furthermore, amphotericin B was not given under optimal circumstances, with premedication to reduce infusion-related toxicity, slow infusion, and with fluid, potassium and magnesium supplements to prevent nephrotoxicity. The major harms were hepatic impairment and gastrointestinal adverse effects with fluconazole and infusion-related toxicity, renal impairment and gastrointestinal adverse effects with amphotericin B. For the 2011 and 2014 updates no additional trials were identified for inclusion.

AUTHORS' CONCLUSIONS

Amphotericin B has been disfavoured in several of the trials through their design or analysis, or both. Since intravenous amphotericin B is the only antifungal agent for which an effect on mortality has been shown, and since it is considerably cheaper than fluconazole, it should be the preferred agent.

Nystatin prophylaxis and treatment in severely immunodepressed patients

BACKGROUND

Nystatin is sometimes used prophylactically in patients with severe immunodeficiency or in the treatment of fungal infection in such patients, although its effect seems to be equivocal.

OBJECTIVES

To study whether nystatin decreases morbidity and mortality when given prophylactically or therapeutically to patients with severe immunodeficiency.

SEARCH METHODS

We searched PubMed from 1966 to 7 July 2014 and the reference lists of identified articles.

SELECTION CRITERIA

Randomised clinical trials comparing nystatin with placebo, an untreated control group, fluconazole or amphotericin B.

DATA COLLECTION AND ANALYSIS

Data on mortality, invasive fungal infection and colonisation were independently extracted by both authors. A random-effects model was used unless the P value was greater than 0.10 for the test of heterogeneity.

MAIN RESULTS

We included 14 trials (1569 patients). The drugs were given prophylactically in 12 trials and as treatment in two. Eleven trials were in acute leukaemia, solid cancer, or bone marrow recipients; one in liver transplant patients; one in critically ill surgical and trauma patients; and one in AIDS patients. Nystatin was compared with placebo in three trials, with fluconazole in 10, and amphotericin B in one; the dose varied from 0.8 MIE to 72 MIE daily and was 2 mg/kg/d in a liposomal formulation. The effect of nystatin was similar to that of placebo on fungal colonisation (relative risk (RR) 0.85, 95% confidence interval (CI) 0.65 to 1.13). There was no statistically significant difference between fluconazole and nystatin on mortality (RR 0.75, 95% CI 0.54 to 1.03) whereas fluconazole was more effective in preventing invasive fungal infection (RR 0.40, 95% CI 0.17 to 0.93) and colonisation (RR 0.50, 95% CI 0.36 to 0.68). There were no proven fungal infections in a small trial that compared amphotericin B with liposomal nystatin. The results were very similar if the three studies that were not performed in cancer patients were excluded. For the 2011 and 2014 updates no additional trials were identified for inclusion.

AUTHORS' CONCLUSIONS

Nystatin cannot be recommended for prophylaxis or the treatment of Candida infections in immunodepressed patients.

Routine versus selective antifungal administration for control of fungal infections in patients with cancer

BACKGROUND

Systemic fungal infection is considered to be an important cause of morbidity and mortality in cancer patients, particularly those with neutropenia. Antifungal drugs are often given prophylactically, or empirically to patients with persistent fever.

OBJECTIVES

To assess whether commonly used antifungal drugs decrease mortality in cancer patients with neutropenia.

SEARCH METHODS

We searched PubMed from 1966 to 7 July 2014 and the reference lists of identified articles.

SELECTION CRITERIA

Randomised clinical trials of amphotericin B, fluconazole, ketoconazole, miconazole, itraconazole or voriconazole compared with placebo or no treatment in cancer patients with neutropenia.

DATA COLLECTION AND ANALYSIS

The two review authors independently assessed trial eligibility and risk of bias, and abstracted data.

MAIN RESULTS

Thirty-two trials involving 4287 patients were included. Prophylactic or empirical treatment with amphotericin B significantly decreased total mortality (relative risk (RR) 0.69, 95% confidence interval (CI) 0.50 to 0.96), whereas the estimated RRs for fluconazole, ketoconazole, miconazole, and itraconazole were close to 1.00. No eligible trials were found with voriconazole. Amphotericin B and fluconazole decreased mortality ascribed to fungal infection (RR 0.45, 95% CI 0.26 to 0.76 and RR 0.42, 95% CI 0.24 to 0.73, respectively). The incidence of invasive fungal infection decreased significantly with administration of amphotericin B (RR 0.41, 95% CI 0.24 to 0.73), fluconazole (RR 0.39, 95% CI 0.27 to 0.57) and itraconazole (RR 0.53, 95% CI 0.29 to 0.97), but not with ketoconazole or miconazole. Effect estimates were similar for those 13 trials that had adequate allocation concealment and were blinded. The reporting of harms was far too variable from trial to trial to allow a meaningful overview. For the 2011 and 2014 updates no additional trials were identified for inclusion.

AUTHORS' CONCLUSIONS

Intravenous amphotericin B was the only antifungal agent that reduced total mortality. It should therefore be preferred when prophylactic or empirical antifungal therapy is introduced in cancer patients with neutropenia.

A survey of current practice with regard to oral care for children being treated for cancer

The aim of the study was to establish current UK oral care practice for children with cancer. A telephone survey of all 22 United Kingdom Children's Cancer Study Group (UKCCSG) centres was undertaken. Nineteen (86%) of the centres reported using guidelines/protocols for mouth care. The use of routine preventive oral care therapies showed the greatest variation between centres. Four centres (18%) did not use any prophylactic oral care therapy other than basic oral hygiene, whereas seven (32%) routinely used a combination of three or more agents. Chlorhexidine was the most frequently administered prophylactic therapy (17/22 centres, 77%), followed by nystatin (11/22 centres, 50%). There was little variation in advice given to parents/patients on basic oral hygiene. Regarding dental check-ups, 9/22 centres (41%) recommended children to attend a hospital-linked dental clinic. Only at 8/22 centres (36%) did children undergo a dental check-up before commencing cancer treatment. The survey identified significant variation in preventive oral care therapies and dental check-ups at the UKCCSG centres. Attention needs to be given to establishing evidence based, effective strategies.

Systemic antifungal drugs for invasive fungal infection in preterm infants

BACKGROUND

Invasive fungal infection is an increasingly common cause of mortality and morbidity in preterm infants. In addition to amphotericin B, a variety of newer antifungal drugs and drug preparations are available for treatment. There is a need to assess their relative merits.

OBJECTIVES

In preterm infants with suspected or confirmed invasive fungal infection, does treatment with newer systemic antifungal drugs or drug preparations, versus conventional amphotericin B alone, reduce mortality and adverse neurodevelopmental outcomes?

SEARCH STRATEGY

We used the standard search strategy of the Cochrane Neonatal Review Group. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2003), MEDLINE (1966 - August 2003), EMBASE (1980 - August 2003), conference proceedings, and previous reviews.

SELECTION CRITERIA

Randomised and quasi-randomised control trials comparing one antifungal agent or combination of agents with another in preterm infants with suspected or confirmed invasive fungal infection.

DATA COLLECTION AND ANALYSIS

We extracted the data using the standard methods of the Cochrane Neonatal Review Group, with separate evaluation of trial quality and data extraction by each author, and synthesis of data using relative risk and risk difference. The pre-specified outcomes were death prior to hospital discharge, longer term neurodevelopment, and adverse drug reactions resulting in discontinuation of therapy.

MAIN RESULTS

We identified only one small trial. This study compared the use of fluconazole with amphotericin B (5-Fluorocytosine added if fungal meningitis present). Three of 11 infants who were treated with fluconazole died and four of 10 infants who were treated with amphotericin B died : Relative risk: 0.68 (95% confidence interval 0.20, 2.33), Risk Difference -0.13 (95% confidence interval -0.53, 0.27) There were not any data on longer term outcomes.

REVIEWER'S CONCLUSIONS

From this one small study there are insufficient data to favour one antifungal agent or combination to reduce mortality and adverse neurodevelopmental outcomes in preterm infants with suspected or confirmed invasive fungal infection. A large randomised controlled trial is required to compare the newer antifungal preparations with conventional amphotericin B. Further research may also determine the relative convenience and cost effectiveness of the available drugs.

Nystatin prophylaxis and treatment in severely immunodepressed patients

BACKGROUND

Nystatin is sometimes used prophylactically in patients with severe immunodeficiency or in the treatment of fungal infection in such patients, although the effect seems to be equivocal.

OBJECTIVES

To study whether nystatin decreases morbidity and mortality when given prophylactically or therapeutically to patients with severe immunodeficiency.

SEARCH STRATEGY

MEDLINE and The Cochrane Library using a comprehensive search strategy, date of last search November 2001. Contacted industry and scanned reference lists.

SELECTION CRITERIA

Randomised trials comparing nystatin with placebo, an untreated control group, fluconazole or amphotericin B.

DATA COLLECTION AND ANALYSIS

Data on mortality, invasive fungal infection and colonisation were extracted by both authors independently. The outcomes were weighted by the inverse variance. A random effects model was used unless p>0.10 for the test of heterogeneity.

MAIN RESULTS

We included 12 trials (1,464 patients). The drugs were given prophylactically in ten trials and as treatment in two. Seven trials were in acute leukaemia, two in cancer, one in liver transplant patients, one in critically ill surgical and trauma patients, and one in AIDS patients. Nystatin had been compared with placebo in three trials and with fluconazole in nine; the dose varied from 1.5 MIE to 72 MIE daily. The effect of nystatin was similar to that of placebo on fungal colonisation (relative risk 0.85, 95% confidence interval 0.65 to 1.13). There was no statistically significant difference between fluconazole and nystatin on mortality (relative risk 0.76, 0.49 to 1.18) whereas fluconazole was more effective in preventing invasive fungal infection (relative risk 0.37, 0.15 to 0.91) and colonisation (relative risk 0.49, 0.34 to 0.70). The results were very similar if the three studies which were not performed in cancer patients were excluded.

REVIEWER'S CONCLUSIONS

Nystatin cannot be recommended for prophylaxis or treatment of Candida infections in immunodepressed patients.

Routine versus selective antifungal administration for control of fungal infections in patients with cancer

BACKGROUND

Systemic fungal infection is considered to be an important cause of morbidity and mortality in cancer patients, particularly those with neutropenia. Antifungal drugs are often given prophylactically, or to patients with persistent fever.

OBJECTIVES

The objective of this review was to assess the effect of antifungal drugs in cancer patients with neutropenia.

SEARCH STRATEGY

We searched the Cochrane Controlled Trials Register and MEDLINE (November 2001) and the reference lists of articles. We searched the proceedings of the ICAAC (from 1990 to 2001, General Meeting of the ASM (from 1990 to 2001), and the European Congress of Clinical Microbiology and Infectious Diseases (1995 to 2001) and contacted researchers in the field.

SELECTION CRITERIA

Randomised trials of amphotericin B, fluconazole, ketoconazole, miconazole, or itraconazole compared with placebo or no treatment in cancer patients with neutropenia.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial eligibility, methodological quality and abstracted data.

MAIN RESULTS

Thirty trials involving 4094 patients were included. Prophylactic or empirical treatment with antifungals as a group had no statistically significant effect on mortality (relative risk 0.95, 95% confidence interval 0.82 to 1.11). The relative risk was smallest for amphotericin B, 0.73 (0.52 to 1.03) (P=0.08). In another review, three trials compared intravenous lipid soluble amphotericin B (AmBisome) with smaller doses of standard intravenous amphotericin B; the relative risk was 0.74 (0.52 to 1.07). Taken together, these results indicate that intravenous amphotericin B might decrease mortality. In contrast, trials with fluconazole, ketoconazole, miconazole and itraconazole failed to find an effect on mortality. The incidence of invasive fungal infection decreased significantly with administration of amphotericin B (relative risk 0.39, 95% CI 0.20 to 0.76), fluconazole (0.39, 0.27 to 0.57) and itraconazole (0.51, 0.27 to 0.96), but not with miconazole or ketoconazole.

REVIEWER'S CONCLUSIONS

Intravenous amphotericin B is the only antifungal agent for which there is evidence suggesting that it might reduce mortality. It should therefore be preferred when prophylactic or empirical antifungal therapy in cancer patients with neutropenia is considered indicated.

Amphotericin B versus fluconazole for controlling fungal infections in neutropenic cancer patients

BACKGROUND

Systemic fungal infection is considered to be an important cause of morbidity and mortality in cancer patients, particularly those with neutropenia. Antifungal drugs are often given prophylactically, or to patients with persistent fever.

OBJECTIVES

To compare the effect of fluconazole and amphotericin B on morbidity and mortality in patients with cancer complicated by neutropenia.

SEARCH STRATEGY

MEDLINE and Cochrane Library (November 2001). Letters, abstracts, and unpublished trials. The industry and authors were contacted.

SELECTION CRITERIA

Randomised trials comparing fluconazole with amphotericin B.

DATA COLLECTION AND ANALYSIS

Data on mortality, invasive fungal infection, colonisation, use of additional (escape) antifungal therapy and adverse effects leading to discontinuation of therapy were extracted by both authors independently.

MAIN RESULTS

Sixteen trials (3760 patients, 341 deaths) were included. In 3 large 3-armed trials, results for amphotericin B were combined with results for nystatin in a "polyene" group. Because nystatin is an ineffective drug in these circumstances, this approach creates a bias in favour of fluconazole. Furthermore, most patients were randomised to oral amphotericin B, which is poorly absorbed and poorly documented. It was unclear whether there was overlap among the "polyene" trials. We were unable to obtain any information to clarify these issues from the trial authors or from Pfizer, the manufacturer of fluconazole. There were no significant differences in effect between fluconazole and amphotericin B, but the confidence intervals were wide. More patients dropped out of the study when they received amphotericin B, but as none of the trials were blinded, decisions on premature interruption of therapy could have been biased. Furthermore, amphotericin B was rarely given under optimal circumstances, with premedication to reduce infusion-related toxicity, slow infusion, and with potassium and magnesium supplements to prevent nephrotoxicity.

REVIEWER'S CONCLUSIONS

Amphotericin B had been disfavoured in several of the trials through their design or analysis. Since intravenous amphotericin B is the only antifungal agent for which there is good evidence suggesting an effect on mortality and is considerably cheaper than fluconazole, it should be preferred.

Development of reference procedures for broth microdilution antifungal susceptibility testing of yeasts with standardized endpoint determination

Standard guidelines for the broth microdilution antifungal susceptibility testing of amphotericin B, flucytosine, fluconazole, miconazole and itraconazole are reported. These are a modification of the method developed by the National Committee for Clinical Laboratory Standards (NCCLS) on the following two points: standardization of the means of endpoint determination and the inclusion of miconazole and itraconazole in the testing. MIC was determined to be when the positive control had a turbidity of 0.2 at the 630 nm wavelength. The endpoint was 80% inhibition for azoles and 100% inhibition for other drugs. The method provided good reproducibility, and a wide range of MIC distribution was observed in all antifungal agents except amphotericin B.

Hazards of inadequate fluconazole dosage to treat deep-seated or systemic Candida albicans infection

We report three cases of deep-seated and systemic Candida albicans infection in which inadequate dosages of fluconazole were used, leading to breakthrough fungaemia, candidal osteomyelitis and endocarditis. The need to modify fluconazole dosage in patients receiving continuous venovenous haemofiltration is discussed.

Azole resistance in Candida

Resistance of Candida to azoles is an increasing problem. Susceptibility testing of Candida against fluconazole and ketoconazole is now feasible and desirable. Good correlation of resistance in vitro with clinical failure of fluconazole therapy has now been shown in mucosal candidiasis. The relationship, if any, between resistance and clinical failure in the context of invasive candidiasis is not clear at present and additional correlative work needs to be done. Monitoring of resistance trends in Candida is clearly important now.