Wait at least 7 days after commencing/changing therapy to reach steady state before collecting blood for analysis. Blood samples for TDM can be collected earlier if efficacy or toxicity are concerns or a loading dose is used.

Collect a 5 mL EDTA (purple top) tube 12 hours (or 6 hours if qid regimen used) after the dose (i.e. trough collection, just before the next dose). Do not use tubes with gel separator.

Monitoring Posaconazole trough concentration at steady state (after 1 week of initiation or change of therapy) can be clinically helpful.

Suggested therapeutic range is > 0.5 mg/L for prophylaxis and > 0.7 mg/L for therapy.