Posaconazole levels

Antifungal agents are assayed by liquid chromatography-tandem mass spectroscopy (LC-MS-MS). The results are highly specific and are not influenced by the use of antifungal combination therapy.


Confirmation of adequate levels in patients receiving posaconazole for treatment or prophylaxis of fungal disease.


Serum 250 µl minimum or 3 mL clotted blood


Drug concentration in mg/L, with advice on target levels. Trough levels should be maintained above 0.7mg/L for prophylaxis and above 1.25mg/L for treatment. If levels are below this - ensure drug is taken with fatty food, consider increasing dose (max 800mg/d) or examining concomitant medications.

95% Turnaround Time:

8 days


The uncertainty of measurement of this assay has been characterised in the following way, a positive control sample at the approximate level a similar level as the cutoff for a prophylactic level, ie 0.7mg/L , tested over 6 months yielded a mean of 0.99 mg/L and a standard deviation of 0.043, thus we estimate that 95% of all samples at this level will have a range from + or - 0.083 (1.96 x 0.043) mg/L.

Page Reviewed: 03/06/19 | Updated by: Kevin Roberts