Monitor hepatic and renal function, electrolyte disturbances (e.g. Ca, Mg, K), CBC, breakthrough fungal infections and adequate oral intake.
Decreased plasma concentrations w/ efavirenz, fosamprenavir, cimetidine, esomeprazole, metoclopramide, phenytoin and rifabutin. May increase plasma concentration of ritonavir and atazanavir. May increase risk of neurotoxicity w/ vinca alkaloids (e.g. vincristine, vinblastine). May increase plasma concentrations of tacrolimus, ciclosporin, midazolam, Ca channel blockers (e.g. verapamil, diltiazem, nifedipine, nicardipine, felodipine) and digoxin. Potentially Fatal: May increase sirolimus blood concentrations. May increase risk of QT prolongation or torsades de pointes of CYP3A4 substrates (e.g. terfenadine, astemizole, cisapride, pimozide, halofantrine, or quinidine). May increase risk of rhabdomyolysis w/ HMG-CoA reductase inhibitors (e.g. atorvastatin, lovastin, simvastatin). May increase risk of ergotism w/ ergot alkaloids (e.g. ergotamine and dihydroergotamine.
Description: Mechanism of Action: Blocks the synthesis of ergosterol, a key component of the fungal cell membrane, through the inhibition of the enzyme lanosterol-14α-demethylase and accumulation of methylated sterol precursors. Posaconazole has activity against Candida spp., Aspergillus spp., Coccidioides immitis, Fonsecaea pedrosoi, and some species of Fusarium and zygomycetes. Pharmacokinetics: Absorption: Slowly absorbed from the GI tract. Absorption may be increased w/ food. Time to peak plasma concentration: Approx 5 hr. Distribution: Plasma protein binding: >98%. Metabolism: Not significantly metabolised; approx 15-17% is metabolised via hepatic glucuronidation. Excretion: Mainly via faeces (77%; 66% as unchanged drug); urine (approx 14%, w/ only trace amounts excreted unchanged). Mean elimination half-life: 35 hr.
Store between 2-8°C. Oral:
Tab: Store between 20-25°C. Oral susp: Store at 25°C.
Anon. Posaconazole. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 09/07/2014.Buckingham R (ed). Posaconazole. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 09/07/2014.McEvoy GK, Snow EK, Miller J et al (eds). Posaconazole. AHFS Drug Information (AHFS DI) [online]. American Society of Health-System Pharmacists (ASHP). https://www.medicinescomplete.com. Accessed 09/07/2014.Noxafil Oral Suspension. U.S. FDA. https://www.fda.gov/. Accessed 14/07/2014.Noxafil Suspension, Tablet Coated, Solution (Merck Sharp & Dohme Corp.). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 09/07/2014.