Treatment
Table 2. Clinical Scenarios Where Antifungal Therapeutic
Drug Monitoring Is Useful
Clinical Scenario Examples, Comment
Populations with increased
pharmacokinetic variability
Impaired gastrointestinal function; hepatic
(voriconazole, posaconazole, itraconazole);
pediatric patients, elderly patients, obese
patients, critically-ill patients
Changing pharmacokinetics Intravenous-to-oral switch, changing GI
function, changing hepatic or renal function,
physiological instability
Interacting medications Patient receiving medication that induce
CYP3A4, antacids, proton-pump inhibitors
(itraconazole capsules, posaconazole suspension),
antiretroviral medications
Possibly corticosteroids (voriconazole)
Severe disease Extensive infection, lesions contiguous with
critical structures, CNS infection, multifocal or
disseminated infection
Compliance Important issue with longer-term consolidation
therapy or secondary prophylaxis
Suspected breakthrough infection TDM can help to establish whether fungal
disease progression occurred in the setting of
inadequate antifungal exposure.
Suspected drug toxicity, especially
neurotoxicity (voriconazole)
Although exposure-response relationships are
described for other toxicities (e.g., hepatotoxicity,
bone disease), the utility of TDM to prevent
their occurrence is less well established.
NB: Additional studies are needed to assess role of TDM for isavuconazole and for
posaconazole extended tablet and intravenous formulations.
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