not affect the exposures of the CYP2D6 /CYP1A2 substrate duloxetine. Other CYP1A2 substrates (e.g. ciprofloxacin, theophylline and caffeine) and CYP2D6 substrates (e.g. desipramine, metoprolol and dextromethorphan) are not expected to require dose adjustments.
Medicinal products renally excreted via transport proteins
Dasabuvir does not inhibit organic anion transporter (OAT1) in vivo as shown by the lack of interaction with tenofovir (OAT1 substrate). In vitro studies show that dasabuvir is not an inhibitor of organic cation transporters (OCT2), organic anion transporters (OAT3), or multidrug and toxin extrusion proteins (MATE1 and MATE2K) at clinically relevant concentrations.
Therefore, dasabuvir is not expected to affect medicinal products which are primarily excreted by the renal route via these transporters (see section 5.2).
Potential for other medicinal products to affect the pharmacokinetics of dasabuvir
Medicinal products that inhibit CYP2C8
Co-administration of dasabuvir with medicinal products that inhibit CYP2C8 (e.g. teriflunomide, deferasirox) may increase dasabuvir plasma concentrations. Strong CYP2C8 inhibitors are contraindicated with dasabuvir (see section 4.3 and Table 2).
Enzyme inducers
Co-administration of dasabuvir with medicinal products that are moderate or strong enzyme inducers is expected to decrease dasabuvir plasma concentrations and reduce its therapeutic effect. Contraindicated enzyme inducers are provided in section 4.3 and Table 2.
Dasabuvir is a substrate of P-gp and BCRP and its major metabolite M1 is a substrate of OCT1 in vitro. Inhibition of P-gp and BCRP is not expected to show clinically relevant increases in exposures of dasabuvir (Table 2).
Dasabuvir M1 metabolite was quantified in all the drug interaction studies. Changes in exposures of the metabolite were generally consistent with that observed with dasabuvir except for studies with CYP2C8 inhibitor, gemfibrozil, where the metabolite exposures decreased by up to 95% and CYP3A inducer, carbamazepine, where the metabolite exposures decreased by only up to 39%.
Drug interaction studies
Recommendations for co-administration of Exviera with ombitasvir/paritaprevir/ritonavir for a number of medicinal products are provided in Table 2.
If a patient is already taking medicinal product(s) or initiating a medicinal product while receiving Exviera and ombitasvir/paritaprevir/ritonavir for which potential for drug interaction is expected, dose adjustment of the concomitant medicinal product(s) or appropriate clinical monitoring should be considered (Table 2).
If dose adjustments of concomitant medicinal products are made due to treatment with Exviera and ombitasvir/paritaprevir/ritonavir, doses should be re-adjusted after administration of Exviera and ombitasvir/paritaprevir/ritonavir is completed.
Table 2 provides the Least Squares Means Ratio (90% Confidence Interval) effect on concentration of dasabuvir and ombitasvir/paritaprevir/ritonavir and concomitant medicinal products.
The direction of the arrow indicates the direction of the change in exposures (Cmax, and AUC) in the paritaprevir, ombitasvir, dasabuvir and the co-administered medicinal product (↑= increase more than 20%, ↓ = decrease more than 20%, ↔ = no change or change less than 20%).
This is not an exclusive list. Ex
