Biktarvy (bictegravir, emtricitabine, tenofovir alafenamide) is indicated for use as a complete regimen for the treatment of HIV 1 infection. However, in specific clinical situations where an intensification of HIV treatment is needed, coadministration with darunavir/cobicistat would be possible from a pharmacokinetic standpoint. Coadministration of bictegravir and darunavir/cobicistat increased bictegravir AUC by 74%. This increase is unlikely to be clinically significant; available dose exposure data, as well as data from phase 2 and phase 3 studies (48 weeks treatment), have shown a good safety profile with up to a 2.4-fold increase in bictegravir AUC. However, coadministration with darunavir/cobicistat (800/150 mg once daily) and tenofovir alafenamide (25 mg once daily) increased tenofovir AUC and Cmax by 224% and 216%, respectively. The recommended dose of 10 mg tenofovir alafenamide with P-gp inhibitors is not possible with Biktarvy which is only available as a fixed dose combination containing 25 mg tenofovir alafenamide, but it should be noted that tenofovir alafenamide has been associated with a large clinical safety profile.

Coadministration has not been studied. In vitro data showed that ketoconazole, a CYP450 inhibitor, can inhibit the metabolism of triclabendazole. As darunavir/cobicistat is an inhibitor of CYP450 enzymes, there is potential to increase levels of triclabendazole if coadministered, however the clinical significance of this interaction is unknown due to the short term dosing of triclabendazole.

Coadministration has not been studied but based on metabolism and clearance a clinically significant interaction is unlikely as less than 14% of a dose of levocetirizine is metabolised. Levocetirizine is mainly eliminated unchanged in the urine through both glomerular filtration and tubular secretion.

Coadministration has not been studied but based on metabolism and clearance a clinically significant interaction is unlikely. Clotrimazole undergoes hepatic metabolism (likely via CYP3A4) and is a moderate inhibitor of CYP3A4. Coadministration of clotrimazole as a pessary or troche is unlikely to cause a clinically significant increase in clotrimazole or darunavir/cobicistat exposure.

Coadministration has not been studied but based on metabolism and clearance a clinically significant interaction is unlikely. Tirzepatide is metabolized by proteolytic cleavage. Tirzepatide delays gastric emptying, and has the potential to impact the absorption of concomitantly administered oral medications. However, based on available interaction studies, a clinically relevant effect is not expected with darunavir/cobicistat.

Coadministration has not been studied but based on metabolism and clearance a clinically significant interaction is unlikely. Tirzepatide is metabolized by proteolytic cleavage. Tirzepatide delays gastric emptying, and has the potential to impact the absorption of concomitantly administered oral medications. However, based on available interaction studies, a clinically relevant effect is not expected with bictegravir, emtricitabine and tenofovir alafenamide.

Coadministration has not been studied. In vitro, triclabendazole and its active sulfoxide metabolite are inhibitors of CYP3A4, and therefore may increase bictegravir exposure. However, due to short term dosing of triclabendazole (usually single dose), the clinical relevance of this interaction is low. Furthermore, renal excretion of unchanged triclabendazole appears to be minimal (<10%); therefore there is little potential for interaction with emtricitabine or tenofovir derived from tenofovir alafenamide. 

Coadministration has not been studied but based on metabolism and clearance a clinically significant interaction is unlikely as less than 14% of a dose of levocetirizine is metabolised. Levocetirizine is mainly eliminated unchanged in the urine through both glomerular filtration and tubular secretion.