Descovy contains tenofovir alafenamide and therefore should not be administered with tenofovir-DF.

Coadministration is contraindicated due to the potential for serious reactions such as myopathy including rhabdomyolysis. Simvastatin is metabolised by CYP3A4 and coadministration may increase concentrations.

Emtricitabine/tenofovir-DF should not be administered with additional tenofovir-DF. Coadministration of tenofovir-DF (300 mg once daily) and emtricitabine (200 mg once daily for 7 days) had no effect on tenofovir AUC, Cmax or Cmin; emtricitabine AUC and Cmax were unaltered and there was a 20% increase in Cmin (n=17).

Emtricitabine/tenofovir-DF should not be administered with additional emtricitabine or with tenofovir alafenamide.

Coadministration has not been studied. The combination of tenofovir-DF (300 mg) and atazanavir (400 mg) reduced atazanavir AUC, Cmax and Cmin decreased by 25%, 21% and 40%, respectively, but increased tenofovir AUC, Cmax and Cmin by 24%, 14% and 22%, respectively. Atazanavir/cobicistat is also expected to increase tenofovir plasma concentrations. Patients should be closely monitored for tenofovir-associated adverse events, including renal disorders. The European SmPC recommends that atazanavir/cobicistat and tenofovir be given together with food. Cobicistat has been shown to decrease estimated creatinine clearance due to inhibition of tubular secretion of creatinine without affecting actual renal glomerular function. Atazanavir/cobicistat should not be coadministered with emtricitabine in patients with creatinine clearance less than 70 ml/min.

Coadministration has not been studied. Metoprolol is mainly metabolized by CYP2D6. Atazanavir/cobicistat could potentially increase metoprolol concentrations although to a moderate extent as cobicistat is a weak inhibitor of CYP2D6. Pharmacokinetic studies between atazanavir and drugs that prolong the PR interval including beta blockers (other than atenolol) have not been performed. An additive effect of atazanavir and these drugs cannot be excluded. Note, PR interval monitoring may be warranted in patients with underlying block or those receiving known atrioventricular nodal blocking agents. The atazanavir/cobicistat SmPC recommends clinical monitoring. A dose reduction of metoprolol may be necessary.

Coadministration with emtricitabine/TAF has not been studied. Coadministration of atazanavir/cobicistat (300/150 mg once daily) and tenofovir alafenamide increased tenofovir alafenamide AUC and Cmax by 75% and 80%. No significant effects were observed on atazanavir pharmacokinetics. When administered with atazanavir/cobicistat, the recommended dose of emtricitabine/tenofovir alafenamide is 200/10 mg once daily (where available). Cobicistat has been shown to decrease estimated creatinine clearance due to inhibition of tubular secretion of creatinine without affecting actual renal glomerular function. Atazanavir/cobicistat should not be coadministered with emtricitabine in patients with creatinine clearance less than 70 ml/min.

Coadministration with emtricitabine/tenofovir-DF has not been studied. Coadministration of tenofovir-DF (300 mg once daily) and atazanavir/ritonavir (300/100 mg once daily) was studied in 12 subjects. Atazanavir AUC, Cmax and Cmin decreased by 25%, 28% and 26%, respectively. Tenofovir AUC, Cmax and Cmin increased by 37%, 34% and 29%, respectively. No dose adjustment is recommended. The increased exposure of tenofovir could potentiate tenofovir associated adverse events, including renal disorders. Renal function should be closely monitored. In HIV-1 infected patients with renal risk factors, the co-administration of tenofovir-DF with a boosted protease inhibitor should be carefully evaluated. Cobicistat has been shown to decrease estimated creatinine clearance due to inhibition of tubular secretion of creatinine without affecting actual renal glomerular function. Atazanavir/cobicistat should not be coadministered with emtricitabine or tenofovir-DF in patients with creatinine clearance less than 70 ml/min.

Coadministration has not been studied but based on metabolism and clearance a clinically significant interaction is unlikely. Metoprolol is mainly metabolized by CYP2D6. Emtricitabine and tenofovir alafenamide do not interact with this metabolic pathway. Dose Descovy according to the concomitant antiretroviral. 

Coadministration has not been studied but based on metabolism and clearance a clinically significant interaction is unlikely. Simvastatin is metabolized by CYP3A4. Emtricitabine and tenofovir alafenamide do not interact with this metabolic pathway. Dose Descovy according to the concomitant antiretroviral.

Coadministration has not been studied but based on metabolism and clearance a clinically significant interaction is unlikely. Metoprolol is mainly metabolized by CYP2D6.

Coadministration has not been studied but based on metabolism and clearance a clinically significant interaction is unlikely. Simvastatin is metabolized by CYP3A4.