Posaconazole
Posaconazole. Broad-spectrum triazole (mucormycosis coverage). Strong CYP3A4 inhibitor without significant CYP2C9/2C19 effect — narrower DDI… Oral half-life 25 h.
Broad-spectrum triazole (mucormycosis coverage). Strong CYP3A4 inhibitor without significant CYP2C9/2C19 effect — narrower DDI profile than voriconazole. Delayed-release tablet improved absorption over the older suspension formulation.
PK: THE SUSPENSION LABEL HALF-LIFE WAS HUNG ON A TABLET-AND-INTRAVENOUS PAPER THAT SAYS THE OPPOSITE — "the half-life (t½) was 25.76 h" intravenously and "a t½ of 25.21 h after fasting" for the tablet, against a stored 35. F 0.42 verifies but is condition-bound: "42.2% in the fasted state and 87.1% under high-fat breakfast conditions". THIS DRUG BIOAVAILABILITY IS NOT A SCALAR AT ALL — across product, dose and food it spans "17.1% and 10.1% under fasted conditions and 59.1% and 49.2% under fed conditions" for the suspension and "58.8% ... under fasted conditions and approached complete absorption under fed conditions" for the tablet, a range from about a tenth to unity — and even for the one modelled cell two sources disagree, 42.2 against 58.8. It is kept, declared as the fasted delayed-release tablet, because a formulation field does not exist. V 297 L is in no abstract and falls OUTSIDE the only published range, "343 to 1341 liters". ka 0.2 reproduces nothing, implying a 12.8 h peak against an observed 4 h, and real absorption needs four to eight transit compartments. INTERACTIONS: THE LAST UNIFORM BLOCK — all three affinities invert through one assumed concentration of 2 µM and two of the notes print the arithmetic. Nothing here is in dispute; the basis simply had no field to live in.
Pharmacokinetics
- Oral — t½ 25.2 h · F 42% · Vd 297 L
- IV — t½ 25.8 h · F 100% · Vd 297 L
Related compounds
- Midazolam — major
- Tacrolimus — major
- Sirolimus — contraindicated
Sources: PMID:19302901, PMID:17542765, PMID:19196220, PMID:31432392, PMID:36607589