home > drugs a-z list > vfend (voriconazole) drug center > vfend (voriconazole) drug - overdosage and contraindications

In clinical trials, there were three cases of accidental overdose. All occurred in pediatric patients who received up to five times the recommended intravenous dose of voriconazole. A single adverse event of photophobia of 10 minutes duration was reported.

There is no known antidote to voriconazole.

Voriconazole is hemodialyzed with clearance of 121 mL/min. The intravenous vehicle, SBECD, is hemodialyzed with clearance of 55 mL/min. In an overdose, hemodialysis may assist in the removal of voriconazole and SBECD from the body.

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.

• VFEND is contraindicated in patients with known hypersensitivity to voriconazole or its excipients. There is no information regarding cross-sensitivity between VFEND (voriconazole) and other azole antifungal agents. Caution should be used when prescribing VFEND to patients with hypersensitivity to other azoles.
• Coadministration of terfenadine, astemizole, cisapride, pimozide or quinidine with VFEND is contraindicated because increased plasma concentrations of these drugs can lead to QT prolongation and rare occurrences of torsade de pointes [see DRUG INTERACTIONS, and CLINICAL PHARMACOLOGY].
• Coadministration of VFEND with sirolimus is contraindicated because VFEND significantly increases sirolimus concentrations [see DRUG INTERACTIONS, and CLINICAL PHARMACOLOGY].
• Coadministration of VFEND with rifampin, carbamazepine and long-acting barbiturates is contraindicated because these drugs are likely to decrease plasma voriconazole concentrations significantly [see DRUG INTERACTIONS, and CLINICAL PHARMACOLOGY].
• Coadministration of VFEND with high-dose ritonavir (400 mg q12h) is contraindicated because ritonavir (400 mg q12h) significantly decreases plasma voriconazole concentrations. Coadministration of voriconazole and low-dose ritonavir (100 mg q12h) should be avoided, unless an assessment of the benefit/risk to the patient justifies the use of voriconazole [see DRUG INTERACTIONS, and CLINICAL PHARMACOLOGY].
• Coadministration of VFEND with rifabutin is contraindicated since VFEND significantly increases rifabutin plasma concentrations and rifabutin also significantly decreases voriconazole plasma concentrations [see DRUG INTERACTIONS, and CLINICAL PHARMACOLOGY].
• Coadministration of VFEND with ergot alkaloids (ergotamine and dihydroergotamine) is contraindicated because VFEND may increase the plasma concentration of ergot alkaloids, which may lead to ergotism [see DRUG INTERACTIONS, CLINICAL PHARMACOLOGY].
• Coadministration of VFEND with St. John's Wort is contraindicated because this herbal supplement may decrease voriconazole plasma concentration [see DRUG INTERACTIONS, and CLINICAL PHARMACOLOGY].

Last reviewed on RxList: 12/6/2011
This monograph has been modified to include the generic and brand name in many instances.