The drug label for Stribild (elvitegravir, cobicistat, emtricitabine, tenofovir disoproxil fumarate; Gilead Sciences) has been updated to include drug interaction information with quetiapine and ledipasvir/sofosbuvir. Additionally, the pharmacodynamics section has been updated with effects on serum creatinine.
When initiating Stribild in patients taking quetiapine, consideration of an alternate antiretroviral therapy is recommended to avoid increased quetiapine exposure. If coadministration is necessary, the quetiapine dose should be reduced to 1/6 of the current dose and the patient should be monitored for quetiapine-associated adverse reactions.
When initiating quetiapine in patients taking Stribild, coadministration is not recommended because the safety of increased tenofovir concentrations in the setting of ledipasvir/sofosbuvir (Harvoni) and Stribild has not been established. The prescribing information for quetiapine should be referred to for initial dosing and titration.
Data from a Phase 1 study (n=30) showed a statistically significant change in estimated GFR from baseline after 7 days of treatment with cobicistat 150mg among patients with an estimated GFR of ≥80mL/min (-9.9±13.1mL/min) and 50–79mL/min (-11.9±7.0mL/min). The decrease in estimated GFR were reversible after discontinuation of cobicistat. No changes in actual GFR from baseline were seen following cobicistat treatment in subjects with estimated GFR of ≥50mL/min. This indicates cobicistat inhibits tubular secretion of creatinine without altering the actual GFR rate.
Stribild is a combination of an HIV-1 integrase strand transfer inhibitor + pharmacokinetic enhancer + nucleos(t)ide analog reverse transcriptase inhibitors. It is indicated as a complete regimen for the treatment of HIV-1 infection in adults who are antiretroviral treatment-naïve or to replace current antiretroviral (ARV) regimen in virologically-suppressed (HIV-1 RNA <50 copies/mL) patients on a stable ARV regimen for at least 6 months with no history of treatment failure or no known substitutions associated with resistance to any component of Stribild.
It is available as 150mg/150mg/200mg/300mg strength fixed-dose tablets.
For more information call (800) 445-3235 or visit Stribild.com.