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Firkus, Danielle

https://orcid.org/0000-0001-6033-5142

Mayo Clinic

Mayo Clinic Health System

Citations 4

A Retrospective Analysis of Itraconazole and Hydroxy-Itraconazole Serum Concentrations Correlation to Clinical Outcomes of Histoplasmosis Treatment
Firkus, Danielle , Stevens, Ryan W., Saleh, Omar Abu , Cole, Kristin, Enzler, Mark J., Haan, Meghan , HERGES, JOSEPH, Jannetto, Paul J. , Vergidis, Paschalis, Rivera, Christina G. , Abu Saleh, Omar M, Rivera, Christina G , Stevens, Ryan W. , Herges, Joseph R. , Vergidis, Paschalis

Therapeutic Drug Monitoring | July 28, 2026 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.1097/ftd.0000000000001513 Get It

Background: Itraconazole is the preferred antifungal agent for mild to moderate histoplasmosis and step-down therapy following amphotericin B treatment. Although hydroxy-itraconazole, a major metabolite of itraconazole, displays antifungal activity comparable with that of the parent compound, its role in therapeutic drug monitoring targets for histoplasmosis remains uncertain. Methods: The objective was to compare clinical outcomes and adverse events using itraconazole parent-compound concentrations alone versus combined itraconazole and hydroxy-itraconazole concentrations in patients treated for histoplasmosis. This retrospective cohort study included adults with probable or proven histoplasmosis who received itraconazole and had at least 1 documented serum concentration. The primary outcome was clinical response across 3 groups: (1) parent (itraconazole parent-compound concentration >1.0 mcg/mL), (2) combined (parent-compound concentration <1.0 mcg/mL with combined itraconazole plus hydroxy-itraconazole >1.0 mcg/mL), and (3) subtherapeutic (failure to reach either threshold). Treatment response and adverse events were analyzed using the Fisher exact test. Results: Among 108 patients (parent, n = 40; combined, n = 40; subtherapeutic, n = 28), response rates differed across groups (parent (95%); combined (90%); subtherapeutic (67.9%); P = 0.006). There was no difference between the parent and combined groups. Adverse events did not differ, although drug discontinuation occurred more frequently in the subtherapeutic group (parent (5%); combined (20%); subtherapeutic (25%); P = 0.04). Conclusions: Patients who failed to achieve either an itraconazole concentration >1 mcg/mL or a combined itraconazole plus hydroxy-itraconazole concentration >1 mcg/mL had lower response rates. Similar outcomes among patients achieving the itraconazole target alone and those achieving the combined target suggest that hydroxy-itraconazole concentrations may contribute to therapeutic drug monitoring targets in histoplasmosis.
Hands-on Education to Increase Comfort and Knowledge Utilizing In-Check TM Inhaler Training Device in Medical Trainees
Strother, Robert K. , Miller, Nathaniel E. , Umbreit, Audrey , Lee, Maddie, Smoak, Julia, Firkus, Danielle , Davis, Amanda, Strother, Robert , Miller, Nathaniel E

Journal of Primary Care & Community Health | June 25, 2026 | Volume: 17 | Issue: No issue available | Pages: No page available

10.1177/21501319261463360 Get It

Introduction Correct inhaler technique is of utmost importance in the optimal delivery of therapeutics utilized for respiratory illnesses. Previous research suggests that the ability of both patients and providers to correctly use these inhalers is sub-optimal and is associated with poorer patient outcomes. Further education about inhaler types and technique as part of residency education could serve to correct these trends. Methods Family medicine residents were taught correct inhaler technique with an inhaler training device (In-Check TM DIAL G16) using a didactic lecture with hands-on teaching exercise utilizing pharmacy interprofessional teaching. We assessed pre- and post-intervention comfort and knowledge of correct inhaler technique. Results Twenty of twenty-seven eligible family medicine residents attended an interdisciplinary workshop with clinical pharmacists with the purpose of improving inhaler technique comfort level and knowledge. A pre- and post-knowledge test and comfort questionnaire were provided to those participating. Comfort levels with prescribing different inhaler types increased after the intervention and knowledge of different inhalers improved. Conclusion Use of an inhaler training device coupled with an interdisciplinary lecture format improved provider knowledge of correct inhaler technique and comfort with prescribing inhalers.
A Retrospective, Comparative Cohort Analysis of the Utilization of Voriconazole-Containing Regimens Versus Itraconazole in the Treatment of Blastomycosis
Schanz, Caitlin , Rivera, Christina G. , Saleh, Omar M. Abu, Clement, Josh , Enzler, Mark J., Firkus, Danielle , Mara, Kristin C. , Vergidis, Paschalis , Stevens, Ryan W. , Schanz, Caitlin C , Mara, Kristin C , Vergidis, Paschalis , Rivera, Christina G , Stevens, Ryan W , Schanz, Caitlin C., Saleh, Omar Abu

Journal of Fungi | April 14, 2026 | Volume: 12 | Issue: 4 | Pages: 279

10.3390/jof12040279 Get It

Itraconazole is the recommended first-line antifungal agent in blastomycosis treatment. However, pharmacokinetic limitations and adverse drug events may necessitate the use of alternative antifungal agents. The primary objective of the study was to retrospectively describe a cohort of patients with blastomycosis who received voriconazole (as partial or complete therapy), for complete or partial treatment, compared to those who received itraconazole alone. Secondary objectives included rationale for voriconazole selection, treatment response, mortality, and adverse drug events. This retrospective multicenter cohort study included adult patients with proven/probable blastomycosis who received itraconazole or voriconazole. Treatment response was evaluated at one year or end of therapy, whichever came first. Mortality outcomes were assessed within 7 days of the last documented azole dose. Propensity score weighting and subgroup analysis were utilized to control confounding variables between cohorts. A total of 119 patients receiving itraconazole and 25 receiving voriconazole as complete or partial treatment were included. Voriconazole was often selected for CNS involvement or after intolerance to alternative azoles. After propensity score weighting, no significant difference in complete or partial treatment response was observed. Rates of all-cause mortality and blastomycosis-related mortality were numerically higher in the voriconazole cohort. Adverse drug event rates were similar between cohorts; however, discontinuation due to adverse events was more common in the voriconazole cohort. Voriconazole was most utilized for the treatment of blastomycosis in cases with CNS involvement or intolerance to other azoles. A statistically significant difference in response rate was not identified between voriconazole-containing or itraconazole-treated patients; however, given limited sample sizes, further data is needed to assess the equivalency of these agents in the treatment of blastomycosis.
Does metabolite matter? Defining target itraconazole and hydroxy‐itraconazole serum concentrations for blastomycosis
Firkus, Danielle , Saleh, Omar Abu , Enzler, Mark J., Jannetto, Paul J. , Mara, Kristin C. , Vergidis, Paschalis , Rivera, Christina G. , Stevens, Ryan W. , Abu Saleh, Omar M, Mara, Kristin C , Vergidis, Paschalis , Rivera, Christina G , Stevens, Ryan W

Mycoses | January 17, 2023 | Volume: 66 | Issue: 5 | Pages: 412-419

10.1111/myc.13565 Get It

AbstractBackgroundItraconazole is the recommended first‐line treatment for mild‐to‐moderate blastomycosis and consolidation treatment of moderate‐to‐severe disease. Itraconazole is metabolised into three metabolites, including an active metabolite hydroxy‐itraconazole. Literature provides little evidence indicating whether therapeutic drug monitoring targets should be based on itraconazole parent compound alone or a sum of itraconazole and hydroxy‐itraconazole serum concentrations.ObjectivesThis study aims to compare clinical outcomes and adverse drug events (ADEs) of combined itraconazole and hydroxy‐itraconazole concentrations versus itraconazole parent compound alone in patients with blastomycosis.Patients/MethodsThis study was a retrospective cohort review of patients ≥18 years with probable or proven Blastomyces infection who received itraconazole with at least one documented serum itraconazole concentration. The primary outcome was rate of partial or complete treatment response across three patient groups: (1) Itraconazole parent compound >1.0 mcg/ml (parent), (2) parent compound <1.0 mcg/ml, but a combined itraconazole and hydroxy‐itraconazole >1.0 mcg/ml (combined) and (3) failure to achieve a combined or parent concentration >1.0 mcg/ml (subtherapeutic) for >75% of the duration of itraconazole therapy.ResultsA total of 80 patients were included (parent = 32, combined = 36, subtherapeutic = 12). No statistically significant difference was observed for rate of partial or complete treatment response (97% parent vs 94% combined, p = .99). Significantly higher mortality due to blastomycosis was observed in patients in the subtherapeutic group (0% parent vs 3% combined vs 25% subtherapeutic, p = .01).ConclusionsThis study supports an itraconazole therapeutic target combining itraconazole and hydroxy‐itraconazole >1.0 mcg/ml for blastomycosis treatment.