Antifungal Therapeutic Drug Monitoring Are Rates Lower Than Use Rates

According to the results of an article published in Open Forum Infectious Diseases, infectious disease specialists are not monitoring antifungal prescriptions at the same rates they are prescribing these interventions.

The American Society for Microbiology (ASM) notes that most fungal infections are common and relatively harmless superficial infections that frequently present as toenail discoloration, itchy ringwork, thrush in the mouth, or vaginal yeast infections. These superficial infections rarely cause life-threatening illnesses, impacting approximately 15% of the global population.

However, invasive fungal infections are among the most deadly communicable diseases, contributing to approximately 1.5 million annual deaths globally. Although invasive fungal infections have a high mortality rate, nearly 80% of all invasive fungal infection deaths can be prevented with proper diagnosis and treatment.

Providers can sometimes treat invasive fungal infections with itraconazole, voriconazole, and poscanoazole. The Infectious Diseases Society of America (IDSA) recommends antifungal therapeutic drug monitoring (TDM) when these medications are prescribed as they have few indications, frequent drug interactions, and variable pharmacokinetic profiles.

Researchers in Open Forum Infectious Diseases surveyed 523 infectious disease specialists on their usage of these drugs and subsequent antifungal TDM.

The analysis revealed that, during treatment, approximately 90% of respondents engaged in any antifungal TDM when prescribing voriconazole. Additionally, only 72% of survey participants reported using antifungal TDM when prescribing itraconazole and posaconazole.

However, fewer participants reported using any antifungal TDM during prophylaxis, with rates as low as 32% for itraconazole. Although the rates for the other two treatments were higher, they were still not up to par with monitoring during treatment, at 55% and 65% for Posaconazole and voriconazole, respectively.

“In conclusion, despite the relatively high self-reported TDM use during antifungal treatment, these survey results revealed opportunities for improvement in adherence to TDM recommendations, specifically regarding itraconazole, posaconazole, and voriconazole prophylaxis. Increased capacity for on-site TDM might help reduce long wait times for test results, particularly in nonacademic hospital settings, and further research is needed to inform optimal TDM practices,” concluded the researchers in the publication.