rine, tacrolimus, amlodipine, rilpivirine and alprazolam. Examples of other CYP3A4 substrates which may require dose adjustment and/or clinical monitoring include calcium channel blockers (e.g. nifedipine), and trazodone. Although buprenorphine and zolpidem are also metabolized by CYP3A, drug interaction studies indicate that no dose adjustment is needed when co-administering these medicinal products with Viekirax with or without dasabuvir (see Table 2).
Medicinal products transported by the OATP family and OCT1
Paritaprevir is an inhibitor of the hepatic uptake transporters OATP1B1 and OATP1B3, and paritaprevir and ritonavir are inhibitors of OATP2B1. Ritonavir is an in vitro inhibitor of OCT1, but the clinical relevance is unknown. Co-administration of Viekirax with or without dasabuvir with medicinal products that are substrates of OATP1B1, OATP1B3, OATP2B1 or OCT1 may increase plasma concentrations of these transporter substrates, potentially requiring dose adjustment/clinical monitoring. Such medicinal products include some statins (see Table 2), fexofenadine, repaglinide and angiotensin II receptor antagonists (e.g., valsartan).
OATP1B1/3 substrates eva luated in drug interaction studies include pravastatin and rosuvastatin (see Table 2).
Medicinal products transported by BCRP
Paritaprevir, ritonavir and dasabuvir are inhibitors of BCRP in vivo. Co-administration of Viekirax with or without dasabuvir together with medicinal products that are substrates of BCRP may increase plasma concentrations of these transporter substrates, potentially requiring dose adjustment/clinical monitoring. Such medicinal products include sulfasalazine, imatinib and some of the statins (see Table 2).
BCRP substrates eva luated in drug interaction studies include rosuvastatin (see Table 2).
Medicinal products transported by P-gp in the intestine
While paritaprevir, ritonavir and dasabuvir are in vitro inhibitors of P-gp, no significant change was observed in the exposure of the P-gp substrate digoxin when administered with Viekirax and dasabuvir. However, co-administration of digoxin with Viekirax without dasabuvir may result in increased plasma concentrations (see Table 2). Viekirax may increase the plasma exposure to medicinal products that are sensitive for changed intestinal P-gp activity (such as dabigatran etexilate).
Medicinal products metabolised by glucuronidation (UGT1A1)
Paritaprevir, ombitasvir and dasabuvir are inhibitors of UGT1A1. Co-administration of Viekirax with or without dasabuvir with medicinal products that are primarily metabolized by UGT1A1 result in increased plasma concentrations of such medicinal products; routine clinical monitoring is recommended for narrow therapeutic index medicinal products (i.e. levothyroxine). See also Table 2 for specific advice on raltegravir and buprenorphine, which have been eva luated in drug interaction studies.
Medicinal products metabolised by CYP2C19
Co-administration of Viekirax with or without dasabuvir can decrease exposures of medicinal products that are metabolized by CYP2C19 (e.g. lansoprazole, esomeprazole, s-mephenytoin), which may require dose adjustment/clinical monitoring. CYP2C19 substrates eva luated in drug interaction studies include omeprazole and escitalopram (see Table 2).
Medicinal products metabolised by CYP2C9
Viekirax a
