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.

mechanism of action

Voriconazole binds and inhibits ergosterol synthesis by inhibiting CYP450-dependent 14-alpha sterol demethylase. The inhibition of 14-alpha sterol demethylase results in a depletion of ergosterol in fungal cell membrane.

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.

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%).

route of elimination

Voriconazole is eliminated via hepatic metabolism with less than 2% of the dose excreted unchanged in the urine.

drug interactions

Abarelix: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Alfentanil: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of alfentanil by decreasing its metabolism. Monitor for increased anesthetic and respiratory depressant effects and consider using lower alfentanil doses or alternate anesthetic.

Alfuzosin: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of alfuzosin by decreasing its metabolism. Use of alfuzosin with strong CYP3A4 inhibitors is contraindicated by the manufacturer.

Almotriptan: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of almotriptan by decreasing its metabolism. The initial and maximum doses should not exceed 6.25 mg and 12.5 mg, respectively during concomitant therapy. Concomitant therapy should be avoided in patients with impaired hepatic or renal function.

Alprazolam: Voriconazole may increase the serum concentration of alprazolam by decreasing its metabolism. Monitor for alprazolam toxicity if voriconazole is initiated or dose increased.

Amiodarone: Additive QTc prolongation may occur. Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of amiodarone by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of amiodarone if voriconazole is initiated, discontinued or dose changed.

Amitriptyline: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Amlodipine: Voriconazole may increase the serum concentration of amlodipine by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of amlodipine if voriconazole is initiated, discontinued or dose changed.

Amobarbital: Amobarbital may reduce serum concentrations and efficacy of voriconazole. Concomitant voriconazole and long-acting barbiturates therapy is contraindicated.

Amoxapine: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Amprenavir: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of amprenavir by decreasing its metabolism. The serum concentration of voriconazole may be increased by amprenavir. Monitor for changes in the therapeutic and adverse effects of both agents if concomitant therapy is initiated, discontinued or if doses are changed.

Apomorphine: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Aprepitant: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of aprepitant by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of aprepitant if voriconazole is initiated, discontinued or dose changed.

Aripiprazole: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of aripiprazole by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of aripiprazole if voriconazole is initiated, discontinued or dose changed.

Arsenic trioxide: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Artemether: Additive QTc-prolongation may occur. Concomitant therapy should be avoided.

Astemizole: Increased risk of cardiotoxicity and arrhythmias

Atazanavir: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of atazanavir by decreasing its metabolism. The serum concentration of voriconazole may be increased by atazanavir. Monitor for changes in the therapeutic and adverse effects of both agents if concomitant therapy is initiated, discontinued or if doses are changed.

Atorvastatin: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of atorvastatin by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of atorvastatin if voriconazole is initiated, discontinued or dose changed.

Benzphetamine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of benzphetamine by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of benzphetamine if voriconazole is initiated, discontinued or dose changed.

Bisoprolol: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of bisoprolol by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of bisoprolol if voriconazole is initiated, discontinued or dose changed.

Bortezomib: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of bortezomib by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of bortezomib if voriconazole is initiated, discontinued or dose changed.

Bosentan: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of bosentan by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of bosentan if voriconazole is initiated, discontinued or dose changed.

Bromazepam: Voriconazole may increase the serum concentration of bromazepam by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of bromazepam if voriconazole is initiated, discontinued or dose changed.

Bromocriptine: Voriconazole may increase the serum concentration of bromocriptine likely by decreasing its metabolism. Concomitant therapy is contraindicated.

Budesonide: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of budesonide by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of budesonide if voriconazole is initiated, discontinued or dose changed.

Buprenorphine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of buprenorphine by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of buprenorphine if voriconazole is initiated, discontinued or dose changed.

Buspirone: Voriconazole may increase the serum concentration of buspirone likely by decreasing its metabolism via CYP3A4. Monitor for changes in the therapeutic and adverse effects of buspirone if voriconazole is initiated, discontinued or dose changed.

Busulfan: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of busulfan by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of busulfan if voriconazole is initiated, discontinued or dose changed.

Butabarbital: Butabarbital may reduce serum concentrations and efficacy of voriconazole. Concomitant voriconazole and long-acting barbiturates therapy is contraindicated.

Butalbital: Butalbital may reduce serum concentrations and efficacy of voriconazole. Concomitant voriconazole and long-acting barbiturates therapy is contraindicated.

Cabergoline: Voriconazole may increase the serum concentration of cabergoline likely by decreasing its metabolism. Concomitant therapy is contraindicated.

Calcitriol: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of calcitriol by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of calcitriol if voriconazole is initiated, discontinued or dose changed.

Capecitabine: Capecitabine, a strong CYP2C9 inhibitor, may increase the serum concentration of voriconazole by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of voriconazole if capecitabine is initiated, discontinued or dose changed.

Carbamazepine: Carbamazepine may reduce serum concentrations and efficacy of voriconazole likely by increasing its metabolism. Concomitant voriconazole and carbamazepine therapy is contraindicated.

Chlordiazepoxide: Voriconazole may increase the serum concentration of chlordiazepoxide by decreasing its metabolism. Monitor for chlordiazepoxide toxicity if voriconazole is initiated or dose increased.

Chloroquine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of chloroquine by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of chloroquine if voriconazole is initiated, discontinued or dose changed.

Chlorpheniramine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of chlorpheniramine by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of chlorpheniramine if voriconazole is initiated, discontinued or dose changed.

Chlorpropamide: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Ciclesonide: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of ciclesonide by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of ciclesonide if voriconazole is initiated, discontinued or dose changed.

Cilostazol: Voriconzole may increase the serum concentration of cilostazol by decreasing its metabolism. Monitor for increased therapeutic/adverse effects of cilostazol and consider reducing the dose during concomitant therapy.

Cinacalcet: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of cinacalcet by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of cinacalcet if voriconazole is initiated, discontinued or dose changed.

Cisapride: Voriconazole may increase the serum concentration and toxicity of cisapride likely by decreasing its metabolism. Additive QTc prolongation may also occur. Concomitant therapy is contraindicated.

Citalopram: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of citalopram by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of citalopram if voriconazole is initiated, discontinued or dose changed.

Clarithromycin: Additive QTc prolongation may occur. Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of clarithromycin by decreasing its metabolism. Clarithromycin may increase the serum concentration of voriconazole by decreasing its metabolism. Consider alternate therapy or monitor for QTc prolongation and changes in the therapeutic and adverse effects of both agents if concomitant therapy is initiated, discontinued or dose changed.

Clobazam: Voriconazole may increase the serum concentration of clobazam by decreasing its metabolism. Monitor for clobazam toxicity if voriconazole is initiated or dose increased.

Clomipramine: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Clonazepam: Voriconazole may increase the serum concentration of clonazepam by decreasing its metabolism. Monitor for clonazepam toxicity if voriconazole is initiated or dose increased.

Clorazepate: Voriconazole may increase the serum concentration of clorazepate by decreasing its metabolism. Monitor for clorazepate toxicity if voriconazole is initiated or dose increased.

Cocaine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of cocaine by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of cocaine if voriconazole is initiated, discontinued or dose changed.

Colchicine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of colchicine by decreasing its metabolism. A dose reduction of colchicine is recommended along with increased monitoring for colchicine toxicity. Concomitant therapy is contraindicated in patients with renal and/or hepatic impairment.

Conivaptan: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of conivaptan by inhibiting its metabolism. Concomitant therapy is contraindicated.

Cyclosporine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of cyclosporine by decreasing its metabolism. Consider reducing the dose of cyclosporine. Monitor cyclosporine serum concentrations and therapeutic and toxic effects if initiating, discontinuing or adjusting voriconazole therapy.

Dantrolene: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of dantrolene by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of dantrolene if voriconazole is initiated, discontinued or dose changed.

Dapsone: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of dapsone by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of dapsone if voriconazole is initiated, discontinued or dose changed.

Darifenacin: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of darifenacin by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of darifenacin if voriconazole is initiated, discontinued or dose changed.

Darunavir: Darunavir may reduce serum concentrations and efficacy of voriconazole. This combination should be avoided unless the potential benefits outweigh the risk of reduced voriconazole efficacy.

Dasatinib: Additive QTc prolongation may occur. Voriconazole, a strong CYP3A4 inhibitor, may also increase the serum concentration of dasatinib by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of dasatinib if voriconazole is initiated, discontinued or dose changed.

Delavirdine: Delavirdine, a strong CYP2C9 inhibitor, may increase the serum concentration of voriconazole by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of voriconazole if delavirdine is initiated, discontinued or dose changed.

Desipramine: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Dexamethasone: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of dexamethasone by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of dexamethasone if voriconazole is initiated, discontinued or dose changed.

Diazepam: Voriconazole may increase the serum concentration of diazepam by decreasing its metabolism. Monitor for diazepam toxicity if voriconazole is initiated or dose increased.

Diclofenac: Voriconazole, a strong CYP2C9 inhibitor, may increase the serum concentration of diclofenac by decreasing its metabolism. Renal impairment may increase the risk of diclofenac adverse effects. Monitor for changes in therapeutic and adverse effects of diclofenac if voriconazole is initiated, discontinued or dose changed.

Didanosine: Didanosine may interfere with the absorption of orally administered voriconazole. Enteric coated didanosine does not exert this effect. Didanosine buffered formulations should be administered at least 2 hours from oral voriconazole administration.

Digitoxin: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of digitoxin by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of digitoxin if voriconazole is initiated, discontinued or dose changed.

Digoxin: Voriconazole may increase the serum concentration of digoxin. Monitor for increased serum concentrations and toxic effects of digoxin if voriconazole is initiated or dose increased.

Dihydroergotamine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of dihydroergotamine by decreasing its metabolism. Concomitant therapy is contraindicated.

Diltiazem: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of diltiazem by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of diltiazem if voriconazole is initiated, discontinued or dose changed.

Disopyramide: Additive QTc prolongation may occur. Voriconazole, a strong CYP3A4 inhibitor, may also increase the serum concentration of disopyramide by decreasing its metabolism. Consider alternate therapy or monitor for QTc prolongation and changes in the therapeutic and adverse effects of disopyramide if voriconazole is initiated, discontinued or dose changed.

Docetaxel: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of docetaxel by decreasing its metabolism. Consider using a non-interacting antifungal or monitor for changes in the therapeutic and adverse effects of docetaxel if voriconazole is initiated, discontinued or dose changed.

Dofetilide: Voriconazole may increase the serum concentration of dofetilide by decreasing its metabolism. Concomitant therapy is contraindicated.

Dolasetron: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Doxepin: Additive QTc prolongation may occur. Voriconazole, a strong CYP3A4 inhibitor, may also increase the serum concentration of doxepin by decreasing its metabolism. Consider alternate therapy or monitor for QTc prolongation and changes in the therapeutic and adverse effects of doxepin if voriconazole is initiated, discontinued or dose changed.

Doxorubicin: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of doxorubicin by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of doxorubicin if voriconazole is initiated, discontinued or dose changed.

Droperidol: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Efavirenz: Efavirenze may decrease the serum concentration of voriconazole likely by increasing its metabolism. Voriconazole may increase the serum concentration of efavirenz by decreasing its metabolism. Consider alternate therapy or adjust doses and monitor for reduced voriconazole efficacy and increased efavirenz adverse effects during concomitant therapy.

Eletriptan: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of eletriptan by decreasing its metabolism. Consider avoiding administration of the two agents within 72 hours of each other. Monitor for changes in the therapeutic and adverse effects of eletriptan if voriconazole is initiated, discontinued or dose changed.

Eplerenone: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of eplerenone by decreasing its metabolism. Concomitant therapy is contraindicated.

Ergoloid mesylate: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of ergoloid mesylates by decreasing their metabolism. Concomitant therapy is contraindicated.

Ergonovine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of ergonovine by decreasing its metabolism. Concomitant therapy is contraindicated.

Ergotamine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of ergotamine by decreasing its metabolism. Concomitant therapy is contraindicated.

Erlotinib: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of erlotinib by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of erlotinib if voriconazole is initiated, discontinued or dose changed.

Erythromycin: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of erythromycin by decreasing its metabolism. Erythromycin may increase the serum concentration of voriconazole by decreasing its metabolism. Additive QTc prolongation may also occur. Consider alternate therapy or monitor for QTc prolongation and changes in the therapeutic and adverse effects of both agents if concomitant therapy is initiated, discontinued or dose changed.

Escitalopram: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of escitalopram by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of escitalopram if voriconazole is initiated, discontinued or dose changed.

Estazolam: Voriconazole may increase the serum concentration of estazolam by decreasing its metabolism. Monitor for estazolam toxicity if voriconazole is initiated or dose increased.

Eszopiclone: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of eszopiclone by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of eszopiclone if voriconazole is initiated, discontinued or dose changed.

Ethosuximide: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of ethosuximide by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of ambrisentan if voriconazole is initiated, discontinued or dose changed.

Etoposide: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of etoposide by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of etoposide if voriconazole is initiated, discontinued or dose changed.

Everolimus: Voriconzole, a strong CYP3A4 inhibitor, may increase the serum concentration of everolimus by decreasing its metabolism. Concurrent therapy should be avoided.

Felbamate: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of felbamate by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of felbamate if voriconazole is initiated, discontinued or dose changed.

Felodipine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of felodipine by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of felodipine if voriconazole is initiated, discontinued or dose changed.

Fentanyl: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of fentanyl by decreasing its metabolism. Adverse effects include life-threatening respiratory depression. Monitor for changes in the therapeutic and adverse effects of fentanyl if voriconazole is initiated, discontinued or dose changed.

Flecainide: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Floxuridine: Floxuridine, a strong CYP2C9 inhibitor, may increase the serum concentration of voriconazole by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of voriconazole if floxuridine is initiated, discontinued or dose changed.

Fluconazole: Fluconazole, a strong CYP2C9 inhibitor, may increase the serum concentration of voriconazole by decreasing its metabolism. Additive QTc prolongation may also occur. Consider alternate therapy or monitor for QTc prolongation and changes in the therapeutic and adverse effects of voriconazole if fluconazole is initiated, discontinued or dose changed.

Flunisolide: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of flunisolide by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of flunisolide if voriconazole is initiated, discontinued or dose changed.

Fluorouracil: Fluorouracil, a strong CYP2C9 inhibitor, may increase the serum concentration of voriconazole by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of voriconazole if fluorouracil is initiated, discontinued or dose changed.

Fluoxetine: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Flupenthixol: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Flurazepam: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of flurazepam by decreasing its metabolism. Monitor for flurazepam toxicity if voriconazole is initiated or dose increased.

Flurbiprofen: Flurbiprofen, a strong CYP2C9 inhibitor, may increase the serum concentration of voriconazole by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of voriconazole if flurbiprofen is initiated, discontinued or dose changed.

Flutamide: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of flutamide by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of flutamide if voriconazole is initiated, discontinued or dose changed.

Fluticasone Propionate: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of fluticasone by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of fluticasone if voriconazole is initiated, discontinued or dose changed.

Fosamprenavir: Voriconazole may increase the serum concentration of fosamprenavir by decreasing its metabolism. Fosamprenavir may increase the serum concentration of voriconazole. Monitor for changes in the therapeutic and adverse effects of both agents if concomitant therapy is initiated, discontinued or if doses are changed.

Foscarnet: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Fosphenytoin: The hydantoin decreases the effect of voriconazole

Gatifloxacin: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Gefitinib: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of gefitinib by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of gefitinib if voriconazole is initiated, discontinued or dose changed.

Gemfibrozil: Gemfibrozil, a strong CYP2C9 inhibitor, may increase the serum concentration of voriconazole by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of voriconazole if gemfibrozil is initiated, discontinued or dose changed.

Halofantrine: Voriconazole may increase the serum concentration of halofantrine by decreasing its metabolism by CYP3A4. Concomitant therapy should be avoided due to the concentration-dependent risk of QTc prolongation related to halofantrine.

Haloperidol: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of haloperidol by decreasing its metabolism. Additive QTc prolongation may also occur. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of haloperidol if voriconazole is initiated, discontinued or dose changed.

Ibuprofen: Ibuprofen, a strong CYP2C9 inhibitor, may increase the serum concentration of voriconazole by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of voriconazole if ibuprofen is initiated, discontinued or dose changed.

Ibutilide: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Ifosfamide: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of ifosfamide by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of ifosfamide if voriconazole is initiated, discontinued or dose changed.

Imatinib: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of imatinib by decreasing its metabolism. Additive QTc prolongation may also occur. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of imatinib if voriconazole is initiated, discontinued or dose changed.

Imipramine: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Indapamide: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Indinavir: Voriconazole may increase the serum concentration of indinavir by decreasing its metabolism. Indinavir may increase the serum concentration of voriconazole. Monitor for changes in the therapeutic and adverse effects of both agents if concomitant therapy is initiated, discontinued or if doses are changed.

Indomethacin: Indomethacin, a strong CYP2C9 inhibitor, may increase the serum concentration of voriconazole by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of voriconazole if indomethacin is initiated, discontinued or dose changed.

Irinotecan: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of irinotecan by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of irinotecan if voriconazole is initiated, discontinued or dose changed.

Isosorbide Dinitrate: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of isosorbide dinitrate by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of isosorbide dinitrate if voriconazole is initiated, discontinued or dose changed.

Isosorbide Mononitrate: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of isosorbide mononitrate by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of isosorbide mononitrate if voriconazole is initiated, discontinued or dose changed.

Isradipine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of isradipine by decreasing its metabolism. Additive QTc prolongation may also occur. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of isradipine if voriconazole is initiated, discontinued or dose changed.

Ixabepilone: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of ixabepilone by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of ixabepilone if voriconazole is initiated, discontinued or dose changed.

Ketamine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of ketamine by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of ketamine if voriconazole is initiated, discontinued or dose changed.

Ketoconazole: Ketoconazole, a strong CYP2C9 inhibitor, may increase the serum concentration of voriconazole by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of voriconazole if ketoconazole is initiated, discontinued or dose changed.

Lapatinib: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of lapatinib by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of lapatinib if voriconazole is initiated, discontinued or dose changed.

Levofloxacin: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Lidocaine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of lidocaine by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of lidocaine if voriconazole is initiated, discontinued or dose changed.

Lopinavir: Lopinavir may reduce serum concentration and efficacy of voriconazole. This combination should be avoided unless the potential benefits outweigh the risk of reduced voriconazole efficacy.

Lovastatin: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of lovastatin by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of lovastatin if voriconazole is initiated, discontinued or dose changed.

Loxapine: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Lumefantrine: Additive QTc-prolongation may occur. Concomitant therapy should be avoided.

Maprotiline: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Maraviroc: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of maraviroc by decreasing its metabolism. A dose reduction in maraviroc is warranted. Monitor for changes in the therapeutic and adverse effects of maraviroc if voriconazole is initiated, discontinued or dose changed.

Mefenamic acid: Mefanamic acid, a strong CYP2C9 inhibitor, may increase the serum concentration of voriconazole by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of voriconazole if mefanamic acid is initiated, discontinued or dose changed.

Mefloquine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of mefloquine by decreasing its metabolism. Additive QTc prolongation may also occur. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of mefloquine if voriconazole is initiated, discontinued or dose changed.

Meloxicam: Voriconazole may increase the serum concentration of meloxicam by decreasing its metabolism via CYP2C9 and CYP3A4. Monitor for changes in the therapeutic and adverse effects of meloxicam if voriconazole is initiated, discontinued or dose changed.

Mesoridazine: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Methadone: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of methadone by decreasing its metabolism. Additive QTc prolongation may also occur. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of methadone if voriconazole is initiated, discontinued or dose changed.

Methotrimeprazine: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Methylergonovine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of methylergonovine by decreasing its metabolism. Concomitant therapy is contraindicated.

Miconazole: Miconazole, a strong CYP2C9 inhibitor, may increase the serum concentration of voriconazole by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of voriconazole if miconazole is initiated, discontinued or dose changed.

Midazolam: Voriconazole may increase the serum concentration of midazolam by decreasing its metabolism. Monitor for midazolam toxicity if voriconazole is initiated or dose increased.

Mirtazapine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of mirtazapine by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of mirtazapine if voriconazole is initiated, discontinued or dose changed.

Modafinil: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of modafinil by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of modafinil if voriconazole is initiated, discontinued or dose changed.

Moricizine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of moricizine by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of moricizine if voriconazole is initiated, discontinued or dose changed.

Moxifloxacin: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Nateglinide: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of nateglinide by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of nateglinide if voriconazole is initiated, discontinued or dose changed.

Nefazodone: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of nefazodone by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of nefazodone if voriconazole is initiated, discontinued or dose changed.

Nelfinavir: Nelfinavir may decrease the serum concentration of voriconazole likely by increasing its metabolism. Voriconazole may increase the serum concentration of nelfinavir by decreasing its metabolism. Consider alternate therapy or adjust doses and monitor for reduced voriconazole efficacy and increased nelfinavir adverse effects during concomitant therapy.

Nicardipine: Nicardipine, a strong CYP2C9 inhibitor, may increase the serum concentration of voriconazole by decreasing its metabolism. Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of nicardipine by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of voriconazole and nicardipine if concomitant therapy is initiated, discontinued or doses are changed.

Nifedipine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of nifedipine by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of nifedipine if voriconazole is initiated, discontinued or dose changed.

Nilotinib: Voriconazole may increase the serum concentration of nilotinib by inhibiting its metabolism by CYP3A4. Additive QTc prolongation may also occur. Concomitant therapy should be avoided.

Nimodipine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of nimodipine by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of nimodipine if voriconazole is initiated, discontinued or dose changed.

Nisoldipine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of nisoldipine by decreasing its metabolism. Concomitant therapy should be avoided.

Nitrendipine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of nitrendipine by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of nitrendipine if voriconazole is initiated, discontinued or dose changed.

Norfloxacin: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Nortriptyline: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Octreotide: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Omeprazole: Voriconazole increases the effect and toxicity of omeprazole

Paclitaxel: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of paclitaxel by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of paclitaxel if voriconazole is initiated, discontinued or dose changed.

Pentamidine: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Perflutren: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Pergolide: Voriconazole may increase the serum concentration of pergolide likely by decreasing its metabolism. Concomitant therapy is contraindicated.

Phencyclidine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of phencyclidine by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of phencyclidine if voriconazole is initiated, discontinued or dose changed.

Phenobarbital: Phenobarbital may reduce serum concentrations and efficacy of voriconazole. Concomitant voriconazole and long-acting barbiturates therapy is contraindicated.

Phenytoin: Voriconazole may increase the serum concentration of phenytoin by decreasing its metabolism. Phenytoin may increase the serum concentration of voriconazole by increasing its metabolism. Consider alternate antifungal therapy or monitor for voriconazole therapy failure and phenytoin toxicity.

Pimozide: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of pimozide by decreasing its metabolism. Increased risk of QTc prolongation and development arrhythmias. Concomitant use is contraindicated.

Pipotiazine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of pipotiazine by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of pipotiazine if voriconazole is initiated, discontinued or dose changed.

Piroxicam: Piroxicam, a strong CYP2C9 inhibitor, may increase the serum concentration of voriconazole by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of voriconazole if piroxicam is initiated, discontinued or dose changed.

Prazepam: Voriconazole may increase the serum concentration of prazepam by decreasing its metabolism. Monitor for prazepam toxicity if voriconazole is initiated or dose increased.

Praziquantel: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of praziquantel by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of praziquantel if voriconazole is initiated, discontinued or dose changed.

Primidone: The barbiturate, primidone, decreases the effect of voriconazole.

Probucol: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Procainamide: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Propafenone: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Protriptyline: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Quetiapine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of quetiapine by decreasing its metabolism. Additive QTc prolongation may also occur. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of quetiapine if voriconazole is initiated, discontinued or dose changed.

Quinidine: Voriconazole may increase the serum concentration of quinidine likely by inhibiting its metabolism by CYP3A4. Additive QTc prolongation may also occur. Consider alternate therapy or monitor for changes in the serum concentration and toxic effects of quinidine if voriconazole is initiated, discontinued or dose changed.

Quinine: Additive QTc prolongation may occur. Concomitant therapy should be avoided.

Ranolazine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of ranolazine by decreasing its metabolism. Additive QTc prolongation may also occur. Concomitant therapy is contraindicated.

Repaglinide: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of repaglinide by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of repaglinide if voriconazole is initiated, discontinued or dose changed.

Rifabutin: Rifabutin may decrease the serum concentration of voriconazole likely by increasing its metabolism via CYP3A enzymes. Voriconazole may increase the serum concentration of rifabutin likely by inhibiting its metabolism via CYP3A. Concomitant therapy is contraindicated.

Rifampin: Rifampin may decrease the serum concentration of voriconazole likely by increasing its metabolism via CYP3A enzymes. Voriconazole may increase the serum concentration of rifampin likely by inhibiting its metabolism via CYP3A. Concomitant therapy is contraindicated.

Rifapentine: Rifapentine may decrease the serum concentration of voriconazole likely by increasing its metabolism via CYP3A enzymes. Voriconazole may increase the serum concentration of rifapentin likely by inhibiting its metabolism via CYP3A. Concomitant therapy is contraindicated.

Risperidone: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Ritonavir: Ritonavir may decrease the serum concentration of voriconazole by increasing its metabolism. Concomitant therapy with high dose ritonavir is contraindicated. Caution should be used with lower doses as decreased voriconazole efficacy may occur.

Rivaroxaban: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of rivaroxaban by decreasing its metabolism. Increased bleed risks may occur. Consider alternate therapy.

Salmeterol: Voriconazole, a strong CYP3A4 inhibitor may increase the serum concentration of salmeterol by decreasing its metabolism. Consider alternate therapy.

Saquinavir: Voriconazole may increase the serum concentration of saquinavir by decreasing its metabolism. Saquinavir may increase the serum concentration of voriconazole. Monitor for changes in the therapeutic and adverse effects of both agents if concomitant therapy is initiated, discontinued or if doses are changed.

Saxagliptin: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of saxagliptin by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of saxagliptin if voriconazole is initiated, discontinued or dose changed.

Sibutramine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of sibutramine by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of sibutramine if voriconazole is initiated, discontinued or dose changed.

Sildenafil: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of sildenafil by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of sildenafil if voriconazole is initiated, discontinued or dose changed.

Simvastatin: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of simvastatin by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of simvastain if voriconazole is initiated, discontinued or dose changed.

Sirolimus: Voriconazole may increase the serum concentration of sirolimus likely by inhibition of CYP3A4-mediated metabolism or p-glyprotein transport of sirolimus. Consider alternate therapy or reduce the dose of sirolimus and monitor serum levels during concomitant therapy.

Sitaxentan: Sitaxsentan, a strong CYP2C9 inhibitor, may increase the serum concentration of voriconazole by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of voriconazole if sitaxsentan is initiated, discontinued or dose changed.

Solifenacin: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of solifenacin by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of solifenacin if voriconazole is initiated, discontinued or dose changed.

Sotalol: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Sparfloxacin: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

St. John's Wort: St. John's Wort may decrease the serum concentration of voriconazole by increasing its elimination. Concomitant therapy is contraindicated.

Sufentanil: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of sufentanil by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of sufentanil if voriconazole is initiated, discontinued or dose changed.

Sulfisoxazole: Sulfisoxazole, a strong CYP2C9 inhibitor, may increase the serum concentration of voriconazole by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of voriconazole if sulfisoxazole is initiated, discontinued or dose changed.

Sunitinib: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of sunitinib by decreasing its metabolism. Additive QTc prolongation may also occur. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of sunitinib if voriconazole is initiated, discontinued or dose changed.

Tacrolimus: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of tacrolimus by decreasing its metabolism. Additive QTc prolongation may also occur. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of tacrolimus if voriconazole is initiated, discontinued or dose changed.

Tadalafil: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of tadalafil by decreasing its metabolism. Concomitant therapy should be avoided if possible due to high risk of tadalafil toxicity.

Tamoxifen: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of tamoxifen by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of tamoxifen if voriconazole is initiated, discontinued or dose changed.

Tamsulosin: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of tamsulosin by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of tamsulosin if voriconazole is initiated, discontinued or dose changed.

Telithromycin: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of telithromycin by decreasing its metabolism. Telithromycin may increase the serum concentration of voriconazole by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of both agents if concomitant therapy is initiated, discontinued or dose changed. QTc interval prolongation may also occur.

Temsirolimus: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of temsirolimus and its active metabolite, sirolimus, by decreasing their metabolism. Concomitant therapy should be avoided.

Teniposide: The strong CYP3A4 inhibitor, Voriconazole, may decrease the metabolism and clearance of Teniposide, a CYP3A4 substrate. Consider alternate therapy or monitor for changes in the therapeutic/adverse effects of Teniposide if Voriconazole is initiated, discontinued or dose changed.

Terfenadine: Increased risk of cardiotoxicity and arrhythmias

Tetrabenazine: Additive QTc prolongation may occur. Concomitant therapy should be avoided.

Theophylline: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of theophylline by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of theophylline if voriconazole is initiated, discontinued or dose changed.

Thioridazine: Additive QTc prolongation may occur. Concomitant use is contraindicated.

Thiothixene: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Tiagabine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of tiagabine by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of tiagabine if voriconazole is initiated, discontinued or dose changed.

Tipranavir: Voriconazole may increase the serum concentration of tipranavir by decreasing its metabolism. Tipranavir may increase the serum concentration of voriconazole. Monitor for changes in the therapeutic and adverse effects of both agents if concomitant therapy is initiated, discontinued or if doses are changed.

Tolbutamide: Tolbutamide, a strong CYP2C9 inhibitor, may decrease the metabolism and clearance of Voriconazole. Consider alternate therapy or monitor for changes in Voriconazole therapeutic and adverse effects if Tolbutamide is initiated, discontinued or dose changed.

Tolterodine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of tolterodine by decreasing its metabolism. Tolterodine is mainly metabolized via the CYP2D6 pathway. This interaction is likely only a concern in patients who are poor CYP2D6 metabolizers. Monitor for changes in the therapeutic and adverse effects of tolterodine if voriconazole is initiated, discontinued or dose changed.

Toremifene: Additive QTc-prolongation may occur, increasing the risk of serious ventricular arrhythmias. Consider alternate therapy. A thorough risk:benefit assessment is required prior to co-administration.

Tramadol: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of tramadol by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of tramadol if voriconazole is initiated, discontinued or dose changed.

Trazodone: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of trazodone by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of trazodone if voriconazole is initiated, discontinued or dose changed.

Triazolam: Voriconazole may increase the serum concentration of triazolam by decreasing its metabolism. Monitor for triazolam toxicity if voriconazole is initiated or dose increased.

Trimipramine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of trimipramine by decreasing its metabolism. Additive QTc prolongation may also occur. Monitor for changes in the therapeutic and adverse effects of trimipramine if voriconazole is initiated, discontinued or dose changed.

Vardenafil: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of vardenafil by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of vardenafil if voriconazole is initiated, discontinued or dose changed.

Venlafaxine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of venlafaxine by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of venlafaxine if voriconazole is initiated, discontinued or dose changed.

Verapamil: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of verapamil by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of verapamil if voriconazole is initiated, discontinued or dose changed.

Vilazodone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vilazodone. imit maximum adult vilazodone dose to 20 mg/day in patients receiving strong CYP3A4 inhibitors.

Vinblastine: Voriconazole, a strong CYP3A4 inhibitor, may decrease the metabolism of Vinblastine. Consider alternate therapy to avoid Vinblastine toxicity. Monitor for changes in the therapeutic/adverse effects of Vinblastine if Voriconazole is initiated, discontinued or dose changed.

Vincristine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of Vincristine by decreasing its metabolism. Consider alternate therapy to avoid Vincristine toxicity. Monitor for changes in the therapeutic and adverse effects of Vincristine if Voriconazole is initiated, discontinued or dose changed.

Vinorelbine: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of Vinorelbine by decreasing its metabolism. Consider alternate therapy to avoid Vinorelbine toxicity. Monitor for changes in the therapeutic and adverse effects of Vinorelbine if Voriconazole is initiated, discontinued or dose changed.

Vorinostat: Additive QTc prolongation may occur. Consider alternate therapy or monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).

Ziprasidone: Additive QTc-prolonging effects may increase the risk of severe arrhythmias. Concomitant therapy should be avoided.

Zolpidem: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of zolpidem by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zolpidem if voriconazole is initiated, discontinued or dose changed.

Zonisamide: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of zonisamide by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zonisamide if voriconazole is initiated, discontinued or dose changed.

Zopiclone: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of zopiclone by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zopiclone if voriconazole is initiated, discontinued or dose changed.

Zuclopenthixol: Additive QTc prolongation may occur. Consider alternate therapy or use caution and monitor for QTc prolongation as this can lead to Torsade de Pointes (TdP).