Beta-lactam allergy risk stratification in a maternity population in Australia: Scope for allergy de-labelling.

BACKGROUND: Unconfirmed beta-lactam allergy in pregnant people has been associated with higher morbidity, unnecessary exposure to broad-spectrum antibiotics and prolonged hospitalisation. There are no published data on beta-lactam allergies in pregnant people in Australia. AIMS: The aim was to describe patient-reported beta-lactam allergies and appropriateness for antibiotic allergy de-labelling in a maternity cohort in Australia. METHODS: Maternity patients aged ≥18 years admitted to our institution between March 2021 and June 2021 with a beta-lactam allergy documented in their electronic medical record were interviewed for details of their allergy. The documented allergies were compared to the allergy history obtained from the interview. Severity of the allergy was rated, and appropriateness for allergy de-labelling was assessed using the Victorian Therapeutics Advisory Group beta-lactam antibiotic allergy assessment tool. RESULTS: One hundred and fifty-three beta-lactam allergies (182 reactions) were reported by 145 patients. Penicillin class antibiotics were the most frequently implicated, including unspecified penicillins (95/153, 62%), amoxicillin (19/153, 13%) and amoxicillin-clavulanate (8/153, 5%). Allergy documentation required amending in 52 of 145 patients (36%); 85 of 153 (56%) of the beta-lactam allergies were considered low risk and potentially appropriate for direct oral re-challenge. CONCLUSION: Beta-lactam allergies were inaccurately documented in more than one third of the maternity patients included in our study. As such, education of maternity care providers about the importance of accurate allergy history taking remains an urgent unmet need. Furthermore, allergy assessment and de-labelling during pregnancy should be considered in maternity patients to optimise antibiotic prescribing and to improve maternal and neonatal health outcomes.

Single-centre study of therapeutic drug monitoring of posaconazole in lung transplant recipients: factors affecting trough plasma concentrations.

Objectives: This study describes therapeutic drug monitoring (TDM) of posaconazole suspension and modified release (MR) tablets in lung transplant (LTx) recipients and evaluates factors that may affect posaconazole trough plasma concentration (Cmin). Methods: A single-centre, retrospective study evaluating posaconazole Cmin in LTx recipients receiving posaconazole suspension or MR tablets between January 2014 and December 2016. Results: Forty-seven LTx patients received posaconazole suspension, and 78 received the MR tablet formulation; a total of 421 and 617 Cmin measurements were made, respectively. Posaconazole was concurrently administered with proton pump inhibitor in ≥ 90% of patients. The median (IQR) of initial posaconazole Cmin following 300 mg daily of posaconazole tablet was significantly higher than that of 800 mg daily of posaconazole suspension [1.65 (0.97-2.13) mg/L versus 0.81 (0.48-1.15) mg/L, P < 0.01]. Variability in posaconazole Cmin was apparent regardless of the formulations prescribed and dose adjustments were routinely undertaken to maintain therapeutic Cmin. A clear dose-response relationship was observed in patients receiving posaconazole MR tablets. Non-specific adverse events (fatigue, tremor, lethargy, sweating, nausea/vomiting and weight loss) were reported in 3/78 (4%) patients receiving posaconazole MR tablets. Posaconazole Cmin in these three patients was determined to be 9.6, 6.2 and 2.3 mg/L. Conclusions: The current study has provided clinically important insights into the TDM of posaconazole in LTx recipients. Routine TDM should be undertaken in LTx recipients receiving posaconazole suspension and/or MR tablets.

Clinical effectiveness of early posaconazole suspension pre-emptive therapy in lung transplant recipients: The Alfred's experience.

Objectives: This study describes the clinical outcomes and therapeutic drug monitoring (TDM) following posaconazole suspension pre-emptive therapy in lung transplant (LTx) recipients. Methods: This was a single-centre, retrospective cohort study evaluating posaconazole suspension pre-emptive therapy in LTx recipients between January 2009 and December 2015. Results: Forty-two LTx recipients were prescribed posaconazole suspension pre-emptively. Aspergillus fumigatus was the most commonly isolated fungal organism. Of the patients receiving posaconazole suspension as the initial antifungal post-LTx, 93% had eradication of colonization at 6 months after commencing therapy. In contrast, only 61% had eradication of fungal colonization when posaconazole suspension was administered following initial therapy with voriconazole. Posaconazole suspension appeared to be well tolerated, although one case was curtailed following concern about abnormal liver function and another due to nausea/vomiting. TDM was performed in 37 patients. The initial median (IQR) trough plasma concentration ( C min ) following 400 mg twice-daily posaconazole suspension was 0.78 (0.46-1.19) mg/L. Doses beyond 800 mg daily did not appear to result in a higher median C min. Conclusions: Early initiation of posaconazole suspension pre-emptive therapy in LTx recipients appears to be well tolerated and may potentially afford favourable clinical outcomes.

Safety, clinical effectiveness and trough plasma concentrations of intravenous posaconazole in patients with haematological malignancies and/or undergoing allogeneic haematopoietic stem cell transplantation: off-trial experience.

OBJECTIVES: This study describes the safety, clinical effectiveness and trough plasma concentration (Cmin) of intravenous (iv) posaconazole, provided as part of Merck Sharp and Dohme Australia's Named Patient Programme (NPP) in non-clinical trial settings. METHODS: A multicentre, retrospective study on the NPP use of iv posaconazole between July 2014 and March 2015 across seven Australian hospitals. RESULTS: Seventy courses of iv posaconazole were prescribed and evaluated in 61 patients receiving treatment for haematological malignancy. Sixty-one courses were prescribed for prophylaxis against invasive fungal disease (IFD), the majority of which (59) were initiated in patients with gastrointestinal disturbances and/or intolerance to previous antifungals. The median (IQR) duration for prophylaxis was 10 (6-15) days. No breakthrough IFD was observed during or at cessation of iv posaconazole. Nine courses of iv posaconazole were prescribed for treatment of IFD with a median (IQR) duration of 19 (7-30) days. Improvement in signs and symptoms of IFD was observed in five cases at cessation of, and six cases at 30 days post-iv posaconazole. Cmin was measured in 39 courses of iv posaconazole, with the initial level taken [median (IQR)] 4 (3-7) days after commencing iv posaconazole. The median (IQR) of initial Cmin was 1.16 (0.69-2.06) mg/L. No severe adverse events specifically attributed to iv posaconazole were documented, although six courses were curtailed due to potential toxicity. CONCLUSIONS: This non-clinical trial experience suggests that iv posaconazole appeared to be safe and clinically effective for prophylaxis or treatment of IFD in patients receiving treatment for haematological malignancies.

The antifungal pipeline for invasive fungal diseases: what does the future hold?

INTRODUCTION: Over the last two decades, we have experienced pressing needs for new additions to the antifungal armamentarium given the emergence of resistant fungi, the growth of at-risk patient populations for invasive fungal diseases (IFD), the high morbidity and mortality associated with IFD. AREAS COVERED: The current review will discuss the five promising antifungal agents for IFD (i.e. fosmanogepix, ibrexafungerp, olorofim, rezafungin, and opelconazole), now in the late-phase clinical studies, and likely to be available for clinical use in the near future. For each agent, we describe its mechanism of action, pharmacokinetic and pharmacodynamic properties, spectrum of activity as well as the safety and efficacy data, including findings from ongoing clinical trials. The potential roles of these novel antifungals in clinical practice and the key considerations for clinical use will also be discussed. EXPERT OPINION: There are unmet needs of these novel agents that should be addressed in the future studies. These include defining their indications and benefits, how to best target them appropriately, surveillance and stewardship of their use.

Contemporary management and clinical outcomes of mucormycosis: A systematic review and meta-analysis of case reports.

With the advent of newer antifungals, optimum treatment of mucormycosis remains to be fully elucidated. This study systematically evaluated the contemporary management and outcomes of mucormycosis. Mucormycosis cases in patients aged ≥18 years published between January 2000 and January 2017 were identified through Ovid MEDLINE and Embase. Of the 3619 articles identified, 600 (851 individual patient cases) were included in the review. Of the 851 patient cases, antifungal treatment details were available for 785. Intravenous (i.v.) amphotericin B formulations remained the most commonly prescribed first-line antifungals (760/785; 96.8%): 88.2% (670/760) were initiated as monotherapy and 11.8% (90/760) as combination antifungal therapy. Posaconazole oral suspension monotherapy was prescribed as an initial antifungal in 11 cases. It was also administered as maintenance or salvage therapy in 39 and 25 cases, respectively. Itraconazole capsule monotherapy (n = 10) was prescribed primarily for cutaneous disease in patients not receiving any immunosuppressive therapy. All-cause 90-day mortality was 41.0% (349/851). Initial treatment with combination antifungals did not reduce 90-day mortality compared with i.v. conventional amphotericin B or i.v. liposomal amphotericin B monotherapy [35/90 (38.9%) vs. 146/369 (39.6%) vs. 91/258 (35.3%), respectively; P = 0.541]. Concomitant surgical and antifungal therapy was associated with significantly lower 90-day mortality compared with treatment with antifungals alone (OR = 0.23, 95% CI 0.13-0.41; P < 0.001). The findings suggest that first-line antifungals with good efficacy remain an urgent unmet need. Whilst surgery is fundamental to improving survival, the clinical utility of combination antifungal therapy or posaconazole monotherapy requires further investigation.