Antifungal–drug interactions that involve CYP-mediated biotransformation of other medications are summarised in Table 1. For a more detailed discussion of drug interactions between mould-active azoles and medicines in general, the reader is referred to more comprehensive reviews.60,61 Interactions involving azoles and benzodiazepines/anxiolytics. All the azoles including posaconazole significantly inhibit CYP3A metabolism of i.v. or oral midazolam.62–65 Itraconazole and fluconazole also significantly inhibit the CYP3A4 metabolism of triazolam.66–69 Voriconazole and posaconazole likely interact with triazolam, but there have been no published data to date to confirm such an interaction. Midazolam and triazolam
are subjected to significant presystemic (‘first-pass’) metabolism, and
thus the interaction between Akt inhibitor these benzodiazepines and the azoles likely results from inhibition of intestinal and hepatic CYP3A4.4 The interaction between the azoles and the benzodiazepines is typically long-lasting, particularly if both drugs are administered orally.62,64,66,69,70 For example, when administered with itraconazole, the interactions persist for up to 4 days after XL184 molecular weight discontinuing the azole.63,67 The itraconazole metabolites likely play a role in the persistence of the interaction.27 Itraconazole metabolites are potent CYP3A4 inhibitors in vitro and the N-desalkyl-itraconazole metabolite has a much longer half-life than the other metabolites or the parent compound.25,27 Moreover, this particular
metabolite substantially contributes to CYP3A4 inhibition for at least 24 h or perhaps more.27 The interactions augment the pharmacodynamic effects of the benzodiazepines including deep and prolonged hypnotic and sedative effects, prolonged 17-DMAG (Alvespimycin) HCl amnesia and reduced psychomotor performance.62,66,70 Unlike midazolam and triazolam, diazepam undergoes little first-pass metabolism, and it is also metabolised by CYP2C19.71 Itraconazole, fluconazole and voriconazole all significantly increase the systemic exposure of diazepam, but the interactions produce little or only moderate changes in the pharmacodynamic effects of this benzodiazepine.71,72 To date there are no published data describing the potential of diazepam to interact with posaconazole. Benzodiazepines that are unaffected by concomitant administration of an azole, e.g. itraconazole, include temazepam, bromazepam and estolam.73–75 Depending on the case, these agents could be considered as alternative benzodiazipines to use. The non-benzodiazepine anxiolytic buspirone should be used cautiously with the azoles. While there are no data for fluconazole, voriconazole or posaconazole, the interaction with itraconazole results in moderate psychomotor deficits.76 Interactions involving azoles and immunosuppressants. The azoles interact with commonly used immunosuppressive agents (i.e. calcineurin inhibitors, corticosteroids, sirolimus).