Echinocandin exposures in obese patients: A scoping review and clinical perspectives

Anidulafungin exposure and population pharmacokinetics in critically ill patients with invasive candidiasis

PURPOSE

Anidulafungin is recommended as a first-line treatment for invasive Candida infections in critically ill patients. Pharmacokinetic (PK) variability is large in critically ill patients, potentially compromising pharmacokinetic-pharmacodynamic (PKPD) target attainment under standard dosing. We aimed to assess anidulafungin exposure, PKPD target attainment, and population (pop)PK in critically ill patients.

METHODS

Adult ICU patients receiving standard anidulafungin dosing [200 mg on day 1, then 100 mg daily] were included (NCT04045366). We performed rich blood sampling on an early (day 2 ± 1) and/or late (day 5 ± 1) treatment day. Using total anidulafungin plasma concentrations, we developed a popPK model (NONMEM7.5) and conducted Monte Carlo simulations (n = 1,000 per virtual patient) to evaluate the impact of patient factors on PKPD target attainment (AUC24h target 83.5 mg×h/L).

RESULTS

Twenty patients contributed 188 anidulafungin concentrations. PKPD target attainment was 45% and 65% on early and late sampling days, respectively. A two-compartment popPK model with first-order elimination described the data. Anidulafungin clearance increased with bodyweight and central volume of distribution increased as serum albumin decreased. Both bodyweight and serum albumin had a clinically relevant impact on PKPD target attainment at day 1 (area under the ROC curve; AUROC 0.82 and 0.62, respectively), and bodyweight on PKPD target attainment at day 14 (AUROC 0.94). Standard anidulafungin dosing regimen fails to achieve adequate target attainment throughout the treatment period.

CONCLUSION

Standard anidulafungin dosing is insufficient for achieving adequate exposure in critically ill patients. An interactive simulation tool is provided to aid dose-finding research and explore different dosing strategies and targets.

Evaluation of clinical outcomes of anidulafungin for the treatment of candidemia in hospitalized critically ill patients with obesity: A multicenter, retrospective cohort study

OBJECTIVES

To evaluate the clinical outcomes of anidulafungin for candidemia treatment in critically ill patients with obesity.

METHODS

A multicenter, retrospective cohort study was conducted in Saudi Arabia for critically ill adults with candidemia who received anidulafungin. Patients with obesity have a body mass index ≥30 kg/m2. The primary outcome was the clinical cure rate.

RESULTS

A total of 146 patients were included, 64 of whom were obese. There were no statistically significant differences in the clinical cure rate (P = 0.63), microbiological cure rate (P = 0.27), or the median time for a clinical cure (P = 0.13) for patients with obesity compared to non-obese patients. The median time for a microbiological cure was longer in non-obese patients than in patients with obesity (P = 0.04). The median hospital length of stay and the median mechanical ventilation durations were numerically longer in patients with obesity.

CONCLUSIONS

Clinical and microbiological cure rates and time for clinical cure were statistically similar for both groups. Considering the study's limitations (especially with a small sample size), it is uncertain if patients with obesity have similar effectiveness to non-obese patients. Future studies with larger sample sizes are warranted to evaluate if obesity negatively impacts anidulafungin's clinical outcomes for candidemia.

Coagulation dysfunction events associated with echinocandins: a real-world study from FDA adverse event reporting system (FAERS) database

BACKGROUND

Echinocandins belong to the fourth generation of antifungals, and there are no systematic studies on their risk in coagulation dysfunction; this study will predict the risk of coagulation dysfunction of echinocandins using the US Food and Drug Administration Adverse Event Reporting System (FAERS) database.

METHOD

Data from January 2004 to March 2024 were obtained from FAERS. We examined the clinical characteristics of the coagulation dysfunction events and conducted disproportionality analysis by using reporting odds ratios (ROR) to compare echinocandins with the full database.

RESULTS

There were 313 reports of coagulation dysfunction related to echinocandins as the primary suspect (PS) drug. The median time to incident for coagulation dysfunction was 3 (interquartile range [IQR] 1-9) days. Compared to triazoles and polyenes, echinocandins have a stronger signal (ROR 3.18, 95%CI 2.81-3.51, p < 0.01) of coagulation dysfunction. Compared to caspofungin and micafungin, anidulafungin has a stronger signal (ROR 6.84, 95%CI 4.83-9.70, p < 0.01). The strongest signal corresponding to disseminated intravascular coagulation (DIC), platelet count decreased, thrombocytopenia, gastrointestinal haemorrhage, cerebral haemorrhage, pulmonary haemorrhage and thrombotic thrombocytopenic purpura (TTP) is micafungin (ROR 27.19, 95%CI 18.49-39.98), micafungin (ROR 3.50, 95%CI 2.36-5.19), anidulafungin (ROR 9.75, 95%CI 5.22-18.19), micafungin (ROR 3.17, 95%CI 2.02-4.97), micafungin (ROR 4.95, 95%CI 2.81-8.72), caspofungin (ROR 20.76, 95%CI 11.77-36.59), micafungin (ROR 20.43, 95%CI 8.49-49.14), respectively.

CONCLUSIONS

For coagulation dysfunction, we found stronger signals for echinocandins than triazoles and polyenes, and stronger signals for anidulafungin than micafungin and caspofungin. Coagulation parameters should be closely monitored while using the respective drugs.

Updated antimicrobial dosing recommendations for obese patients

The prevalence of obesity has increased considerably in the last few decades. Pathophysiological changes in obese patients lead to pharmacokinetic (PK) and pharmacodynamic (PD) alterations that can condition the correct exposure to antimicrobials if standard dosages are used. Inadequate dosing in obese patients can lead to toxicity or therapeutic failure. In recent years, additional antimicrobial PK/PD data, extended infusion strategies, and studies in critically ill patients have made it possible to obtain data to provide a better dosage in obese patients. Despite this, it is usually difficult to find information on drug dosing in this population, which is sometimes contradictory. This is a comprehensive review of the dosing of different types of antimicrobials (antibiotics, antifungals, antivirals, and antituberculosis drugs) in obese patients, where the literature on PK and possible dosing strategies in obese adults was critically assessed.

Optimizing anidulafungin exposure across a wide adult body size range

Echinocandins like anidulafungin are first-line therapies for candidemia and invasive candidiasis, but their dosing may be suboptimal in obese patients. Our objective was to quantify anidulafungin exposure in a cohort of adults across a wide body size range to test if body size affects anidulafungin pharmacokinetics (PK). We enrolled 20 adults between the ages of 18 and 80 years, with an equal distribution of patients above and below a body mass index of 30 kg/m2. A single 100-mg dose of anidulafungin was administered, followed by intensive sampling over 72 h. Population PK analysis was used to identify and compare covariates of anidulafungin PK parameters. Monte Carlo simulations were performed to compute the probability of target attainment (PTA) based on alternative dosing regimens. Participants (45% males) had a median (range) age of 45 (21-78) years and a median (range) weight of 82.7 (42.4-208.3) kg. The observed median (range) of AUC0-∞ was 106.4 (51.9, 138.4) mg∙h/L. Lean body weight (LBW) and adjusted body weight (AdjBW) were more influential than weight as covariates of anidulafungin PK parameters. The conventional 100 mg daily maintenance is predicted to have a PTA below 90% in adults with an LBW > 55 kg or an AdjBW > 75 kg. A daily maintenance dose of 150-200 mg is predicted in these heavier adults. Anidulafungin AUC0-∞ declines with increasing body size. A higher maintenance dose will increase the PTA compared to the current approach in obese patients.

Antimicrobials in patients with hematologic malignancies and recipients of hematopoietic cell transplantation and other cellular therapies

BACKGROUND

Appropriate use of antimicrobials for hematologic malignancy, hematopoietic stem cell transplant recipients, and other cellular therapies is vital, with infection causing significant morbidity and mortality in this unique population of immunocompromised hosts. However, often in this population the choice and management of antimicrobial therapy is complex. When selecting an antimicrobial agent, key considerations include the need for dose adjustments due to renal or hepatic impairment, managing drug interactions, the potential for additive drug toxicity among those receiving polypharmacy and therapeutic drug monitoring. Other factors include leveraging pharmacodynamic principles to enable optimization of directed therapy against challenging pathogens, as well as judicious use of antimicrobials to limit drug resistance and adverse drug reactions.

SUMMARY

This review summarizes the clinical considerations for commonly used antimicrobials in this setting, including antibacterial, antiviral, and antifungal agents.