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Information |
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Drug Groups
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approved; investigational |
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Description
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Voriconazole (Vfend?, Pfizer) is a triazole antifungal medication used to treat serious fungal infections. It is used to treat invasive fungal infections that are generally seen in patients who are immunocompromised. These include invasive candidiasis, invasive aspergillosis, and emerging fungal infections. |
| Indication |
For the treatment of esophageal candidiasis, invasive pulmonary aspergillosis, and serious fungal infections caused by Scedosporium apiospermum and Fusarium spp. |
| Pharmacology |
Voriconazole is a triazole antifungal agent indicated for use in the treatment of fungal infections including invasive aspergillosis, esophageal candidiasis, and serious fungal infections caused by Scedosporium apiospermum (asexual form of Pseudallescheria boydii) and Fusarium spp. including Fusarium solani. Fungal plasma membranes are similar to mammalian plasma membranes, differing in having the nonpolar sterol ergosterol, rather than cholesterol, as the principal sterol. Membrane sterols such as ergosterol provide structure, modulation of membrane fluidity, and possibly control of some physiologic events. Voriconazole effects the formation of the fungal plasma membrane by indirectly inhibiting the biosynthesis of ergosterol. This results in plasma membrane permeability changes and inhibition of growth. |
| Toxicity |
The minimum lethal oral dose in mice and rats was 300 mg/kg (equivalent to 4 and 7 times the recommended maintenance dose (RMD), based on body surface area). At this dose, clinical signs observed in both mice and rats included salivation, mydriasis, titubation (loss of balance while moving), depressed behavior, prostration, partially closed eyes, and dyspnea. Other signs in mice were convulsions, corneal opacification and swollen abdomen. |
| Affected Organisms |
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| Biotransformation |
Hepatic. The major metabolite of voriconazole is the N-oxide, which accounts for 72% of the circulating radiolabelled metabolites in plasma. Since this metabolite has minimal antifungal activity, it does not contribute to the overall efficacy of voriconazole. |
| Absorption |
The oral bioavailability is estimated to be 96% (CV 13%). |
| Protein Binding |
58% |
| Elimination |
Voriconazole is eliminated via hepatic metabolism with less than 2% of the dose excreted unchanged in the urine. |
| Distribution |
* 4.6 L/kg |
| References |
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Herbrecht R, Denning DW, Patterson TF, Bennett JE, Greene RE, Oestmann JW, Kern WV, Marr KA, Ribaud P, Lortholary O, Sylvester R, Rubin RH, Wingard JR, Stark P, Durand C, Caillot D, Thiel E, Chandrasekar PH, Hodges MR, Schlamm HT, Troke PF, de Pauw B: Voriconazole versus amphotericin B for primary therapy of invasive aspergillosis. N Engl J Med. 2002 Aug 8;347(6):408-15.
[Pubmed]
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Patterson TF, Boucher HW, Herbrecht R, Denning DW, Lortholary O, Ribaud P, Rubin RH, Wingard JR, DePauw B, Schlamm HT, Troke P, Bennett JE: Strategy of following voriconazole versus amphotericin B therapy with other licensed antifungal therapy for primary treatment of invasive aspergillosis: impact of other therapies on outcome. Clin Infect Dis. 2005 Nov 15;41(10):1448-52. Epub 2005 Oct 13.
[Pubmed]
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Kullberg BJ, Sobel JD, Ruhnke M, Pappas PG, Viscoli C, Rex JH, Cleary JD, Rubinstein E, Church LW, Brown JM, Schlamm HT, Oborska IT, Hilton F, Hodges MR: Voriconazole versus a regimen of amphotericin B followed by fluconazole for candidaemia in non-neutropenic patients: a randomised non-inferiority trial. Lancet. 2005 Oct 22-28;366(9495):1435-42.
[Pubmed]
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Ally R, Schurmann D, Kreisel W, Carosi G, Aguirrebengoa K, Dupont B, Hodges M, Troke P, Romero AJ: A randomized, double-blind, double-dummy, multicenter trial of voriconazole and fluconazole in the treatment of esophageal candidiasis in immunocompromised patients. Clin Infect Dis. 2001 Nov 1;33(9):1447-54. Epub 2001 Sep 26.
[Pubmed]
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Walsh TJ, Pappas P, Winston DJ, Lazarus HM, Petersen F, Raffalli J, Yanovich S, Stiff P, Greenberg R, Donowitz G, Schuster M, Reboli A, Wingard J, Arndt C, Reinhardt J, Hadley S, Finberg R, Laverdiere M, Perfect J, Garber G, Fioritoni G, Anaissie E, Lee J: Voriconazole compared with liposomal amphotericin B for empirical antifungal therapy in patients with neutropenia and persistent fever. N Engl J Med. 2002 Jan 24;346(4):225-34.
[Pubmed]
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