ons for future therapy are not known.
Use with glucocorticoids metabolised by CYP3A (e.g. fluticasone)
Caution should be used when administering Viekirax with fluticasone or other glucocorticoids that are metabolised by CYP3A4. Concomitant use of inhaled glucocorticoids metabolised with CYP3A can increase systemic exposures of the glucocorticoids, and cases of Cushing's syndrome and subsequent adrenal suppression have been reported with ritonavir-containing regimens. Concomitant use of Viekirax and glucocorticoids, particularly long-term use, should only be initiated if the potential benefit of treatment outweighs the risk of systemic corticosteroid effects (see section 4.5).
Use with colchicine
The interaction between Viekirax with or without dasabuvir and colchicine has not been eva luated. A reduction in colchicine dosage or an interruption of colchicine treatment is recommended in patients with normal renal or hepatic function if treatment with Viekirax with or without dasabuvir is required (see section 4.5). In patients with renal or hepatic impairment, use of colchicine with Viekirax with or without dasabuvir is contraindicated (see section 4.3 and 4.5).
Use with statins
Simvastatin, lovastatin and atorvastatin are contraindicated (see section 4.3 and 4.5).
Rosuvastatin
Viekirax with dasabuvir is expected to increase the exposure to rosuvastatin more than 3-fold. If rosuvastatin treatment is required during the treatment period, the maximum daily dose of rosuvastatin should be 5 mg (see section 4.5, Table 2).The increase in rosuvastatin when combined with Viekirax without dasabuvir is less pronounced. In this combination, the maximum daily dose of rosuvastatin should be 10 mg (see section 4.5, Table 2).
Pitavastatin and fluvastatin
The interactions between pitavastatin and fluvastatin and Viekirax have not been investigated. Theoretically, Viekirax with and without dasabuvir is expected to increase the exposure to pitavastatin and fluvastatin. A temporary suspension of pitavastatin/fluvastatin is recommended for the duration of treatment with Viekirax. If statin treatment is required during the treatment period, a switch to a reduced dose of pravastatin/rosuvastatin is possible (see section 4.5, Table 2).
Treatment of patients with HIV co-infection
Low dose ritonavir, which is part of the fixed dose combination Viekirax, may select for PI resistance in HIV co-infected patients without ongoing antiretroviral therapy. HIV co-infected patients without suppressive antiretroviral therapy should not be treated with Viekirax.
Drug interactions need to be carefully taken into account in the setting of HIV co-infection (for details see section 4.5, Table 2).
Atazanavir can be used in combination with Viekirax and dasabuvir, if administered at the same time. To be noted, atazanavir should be taken without ritonavir, since ritonavir 100 mg once daily is provided as part of Viekirax. The combination carries an increased risk for hyperbilirubinemia (including ocular icterus), in particular when ribavirin is part of the hepatitis C regimen.
Darunavir, dosed 800 mg once daily, if administered at the same time as Viekirax and dasabuvir, can be used in the absence of extensive PI resistance (darunavir exposure lowered). To be noted, darunavir should be taken without ritonavir, since ritonavir 100 mg once daily is provided as part of Vie
