Home › Compound Library › Posaconazole (Noxafil)

Posaconazole (Noxafil)

Antibioticprescriptionoral · predicted

Second-generation triazole antifungal with the broadest spectrum of approved azoles, including Aspergillus, Mucorales (zygomycetes), Candida, Cryptococcus, and endemic fungi. Delayed-release tablet 300 mg PO BID day 1 then 300 mg QD, preferred formulation due to superior and less food-dependent PK than oral suspension. IV formulation also available. Plasma half-life ~27h. Extensive tissue distribution. Minimal CYP3A4 metabolism as substrate but strong CYP3A4 inhibitor (many drug interactions). TDM recommended (trough >1 mg/L for prophylaxis, >1-1.25 mg/L for treatment).

Projected serum levels — 300 mg, once daily

Posaconazole (Noxafil)
Posaconazole (Noxafil) modeled serum levels, 300 mg once daily over 15 days Population-based pharmacokinetic estimate. Steady state reached after approximately 5 days. 0 250 500 750 1k Day 0 Day 4 Day 8 Day 11 Day 15 Time on a regular schedule ≈ steady state · day 5
Posaconazole (Noxafil) modeled serum levels with a loading dose of 900 mg, then 300 mg once daily The first dose is larger so levels approach steady state faster. 0 250 500 750 1k Day 0 Day 4 Day 8 Day 11 Day 15 Time on a regular schedule

Maintenance schedule: 300 mg once daily (oral).

Loading schedule: 900 mg on day 1, then 300 mg once daily — reaching therapeutic levels sooner.

Modeled steady state after ~5 days: peak ≈ 541 mg, trough ≈ 435 mg body load. Population-based estimate over 15 days for a 300 mg dose at a 70 kg reference body mass — the interactive app scales curves to your doses, timing, and body mass.

Key facts

Category
Antibiotic
Route modeled
Oral
Model confidence
predicted
Half-life
27 h
Common dose
300 mg
Suggested maximum
400 mg/day
Reference dose range
150–400 mg (single dose)
Suggested cadence
once daily
Validated against
300 mg oral — Cmax 1.5 mg/L at 4 h

Documented interactions

  • danger
    7-Hydroxymitragynine (7-OH) + Posaconazole (Noxafil) CYP inhibition

    Posaconazole (Noxafil) reversible_inhibitor of CYP3A4 predicted to change 7-Hydroxymitragynine (7-OH) AUC by ~2.20x

  • danger
    Alfuzosin (Uroxatral) + Posaconazole (Noxafil) CYP inhibition

    Posaconazole (Noxafil) reversible_inhibitor of CYP3A4 predicted to change Alfuzosin (Uroxatral) AUC by ~3.33x

  • danger
    Alprazolam (Xanax) + Posaconazole (Noxafil) CYP inhibition

    Posaconazole (Noxafil) reversible_inhibitor of CYP3A4 predicted to change Alprazolam (Xanax) AUC by ~3.33x

  • danger
    Amlodipine (Norvasc) + Posaconazole (Noxafil) CYP inhibition

    Posaconazole (Noxafil) reversible_inhibitor of CYP3A4 predicted to change Amlodipine (Norvasc) AUC by ~3.33x

  • danger
    Anastrozole (Arimidex) + Posaconazole (Noxafil) CYP inhibition

    Posaconazole (Noxafil) reversible_inhibitor of CYP3A4 predicted to change Anastrozole (Arimidex) AUC by ~2.68x

  • danger
    Astaxanthin + Posaconazole (Noxafil) CYP inhibition

    Posaconazole (Noxafil) reversible_inhibitor of CYP3A4 predicted to change Astaxanthin AUC by ~3.33x

Serum checks 448 modeled interaction pairings for posaconazole (noxafil) across your whole stack — absorption conflicts, enzyme inhibition, and nutrient depletion included.

Research behind this entry

  1. Pharmacokinetics of posaconazole Krishna G et al. · Pharmacotherapy, 2007 DOI

    Comprehensive PK review: absorption dependent on formulation and food, ~27h half-life, minimal renal excretion, and rationale for TDM.

  2. Posaconazole vs. fluconazole or itraconazole prophylaxis in patients with neutropenia Cornely OA et al. · New England Journal of Medicine, 2007 DOI

    Pivotal trial establishing posaconazole superiority for antifungal prophylaxis in prolonged neutropenia (AML/MDS induction).

2 published studies referenced in the app, each with a plain-language summary.