Unless otherwise specified, drug interaction studies have been performed in healthy adult male subjects using multiple dosing to steady state with oral voriconazole at 200 mg twice daily (BID). These results are relevant to other populations and routes of administration.
Voriconazole should be administered with caution in patients with concomitant medication that is known to prolong QT interval.
When there is also a potential for voriconazole to increase the plasma concentrations of substances metabolised by CYP3A4 isoenzymes (certain antihistamines, quinidine, cisapride, pimozide) co-administration is contraindicated.
Interaction table: Interactions between voriconazole and other medicinal products are listed in the table as follows (once daily as "QD", twice daily as "BID", three times daily as "TID" and not determined as "ND"). The direction of the arrow for each pharmacokinetic parameter is based on the 90% confidence interval of the geometric mean ratio being within (↔), below (↓) or above (↑) the 80-125% range.
The asterisk (*) indicates a two-way interaction. AUCτ, AUCt and AUC0-∞ represent area under the curve over a dosing interval, from time zero to the time with detectable measurement and from time zero to infinity, respectively.
The interactions in the table are presented in the following order: contraindications, those requiring dose adjustment and careful clinical and/or biological monitoring, and finally those that have no significant pharmacokinetic interaction but may be of clinical interest in this therapeutic field. (See Tables 3a and 3b.)

