Drug Interactions between cobicistat / darunavir / emtricitabine / tenofovir alafenamide and rosuvastatin

ADJUST DOSE: Coadministration with protease inhibitors may significantly increase the plasma concentrations of rosuvastatin. The mechanism may involve inhibition of OATP1B1-mediated hepatic uptake and/or BCRP-mediated intestinal and hepatobiliary efflux. In 15 healthy volunteers, administration of rosuvastatin 20 mg once a day with lopinavir-ritonavir 400 mg-100 mg twice a day for 7 days was associated with an approximately 5-fold increase in rosuvastatin steady-state peak plasma concentration (Cmax) and a 2-fold increase in systemic exposure (AUC) compared to administration of rosuvastatin alone. One subject had asymptomatic creatine phosphokinase elevation 17 times the upper limit of normal (ULN) and another had liver function test elevation between 1.1 and 2.5 times ULN. In a study with 11 subjects, administration of rosuvastatin 5 mg once daily in combination with once daily morning doses of ombitasvir/paritaprevir/ritonavir (25 mg/150 mg/100 mg) plus twice daily doses of dasabuvir resulted in increases of rosuvastatin Cmax and AUC by approximately 7.1- and 2.6-fold, respectively. Likewise, atazanavir/ritonavir 300 mg/100 mg given once daily for 8 days increased the Cmax and AUC of a single 10 mg dose of rosuvastatin by 7.0- and 3.1-fold, respectively. High levels of HMG-CoA reductase inhibitory activity in plasma is associated with an increased risk of musculoskeletal toxicity. Myopathy manifested as muscle pain and/or weakness associated with grossly elevated creatine kinase exceeding ten times the upper limit of normal has been reported occasionally. Rhabdomyolysis has also occurred rarely, which may be accompanied by acute renal failure secondary to myoglobinuria and may result in death.

MANAGEMENT: The benefits of using rosuvastatin with protease inhibitors should be carefully weighed against the potentially increased risk of myopathy including rhabdomyolysis. If coadministration is required, rosuvastatin should be initiated at the lowest effective dosage and not exceed 10 mg per day when prescribed with lopinavir-ritonavir, atazanavir-ritonavir, atazanavir-cobicistat, or ombitasvir/paritaprevir/ritonavir plus dasabuvir. The dosage of rosuvastatin should be limited to 20 mg once a day when used with darunavir-cobicistat. Nirmatrelvir-ritonavir product labeling advises temporary discontinuation of rosuvastatin be considered during treatment with nirmatrelvir-ritonavir. Alternatively, a different HMG-CoA reductase inhibitor such as fluvastatin may be considered. All patients receiving statin therapy should be advised to promptly report any unexplained muscle pain, tenderness or weakness, particularly if accompanied by fever, malaise and/or dark colored urine. Therapy should be discontinued if creatine kinase is markedly elevated in the absence of strenuous exercise or if myopathy is otherwise suspected or diagnosed.

MONITOR: Coadministration of tenofovir and darunavir-ritonavir or darunavir-cobicistat may result in increased plasma concentrations of tenofovir and darunavir. Increased tenofovir plasma concentration may increase the risk for tenofovir-related renal adverse effects, including renal impairment, renal failure, elevated creatinine, and Fanconi syndrome. The mechanism of this interaction is unknown; however, increased tenofovir concentrations may be related to inhibition of P-glycoprotein by darunavir, cobicistat, or ritonavir in the renal tubules. Cobicistat may decrease estimated creatinine clearance via inhibition of tubular secretion of creatinine; however, renal glomerular function does not appear to be affected. In 12 study subjects, administration of darunavir-ritonavir (300 mg-100 mg twice daily) with tenofovir (300 mg once daily) increased the systemic exposure (AUC) and trough plasma concentration (Cmin) of darunavir by 21% and 24%, respectively, compared to administration without tenofovir. Tenofovir AUC and Cmin also increased by 22% and 37%, respectively, in the presence of darunavir-ritonavir. Data are lacking to determine whether concomitant use of tenofovir with cobicistat-containing regimens is associated with a greater risk of renal complications compared with regimens that do not include cobicistat.

MANAGEMENT: Caution and close monitoring of renal function is recommended if darunavir-ritonavir or darunavir-cobicistat is to be used in combination with tenofovir, particularly in patients with risk factors for renal impairment. No dose adjustments appear necessary during coadministration of darunavir-ritonavir with tenofovir. However, initiation of cobicistat or cobicistat-containing regimens is not recommended in patients with CrCl less than 70 mL/min if any coadministered medicine requires dose adjustment based on renal function (including tenofovir) or is nephrotoxic.

MONITOR: Concomitant use of tenofovir with cobicistat may increase the risk for tenofovir-related renal adverse effects, including renal impairment, renal failure, elevated creatinine, and Fanconi syndrome. The mechanism of this interaction has not been described. Cobicistat may decrease estimated creatinine clearance via inhibition of tubular secretion of creatinine; however, renal glomerular function does not appear to be affected. When given concomitantly with cobicistat, the systemic exposure (AUC) and trough plasma concentrations (Cmin) of tenofovir was also increased by 23% and 55%, respectively. However, data are lacking to determine whether concomitant use of tenofovir with cobicistat-containing regimens is associated with a greater risk of renal complications compared with regimens that do not include cobicistat.

MANAGEMENT: Initiation of cobicistat or cobicistat-containing regimens is not recommended in patients with CrCl less than 70 mL/min if any coadministered medicine requires dose adjustment based on renal function (including tenofovir), or is nephrotoxic. If concomitant therapy is necessary, monitoring of renal function is recommended, particularly in patients with risk factors for renal impairment.

MONITOR: Coadministration with cobicistat may increase the plasma concentrations of rosuvastatin. The proposed mechanism is cobicistat inhibition of the OATP1B1-mediated hepatic uptake of rosuvastatin. In 10 healthy volunteers, administration of a single 10 mg dose of rosuvastatin in combination with a 150 mg dose each of cobicistat and elvitegravir increased mean rosuvastatin peak plasma concentration (Cmax) and systemic exposure (AUC) by 89% and 38%, respectively. High levels of HMG-CoA reductase inhibitory activity in plasma is associated with an increased risk of musculoskeletal toxicity. Myopathy manifested as muscle pain and/or weakness associated with grossly elevated creatine kinase exceeding ten times the upper limit of normal has been reported occasionally. Rhabdomyolysis has also occurred rarely, which may be accompanied by acute renal failure secondary to myoglobinuria and may result in death.

MANAGEMENT: Caution is advised if rosuvastatin is prescribed with cobicistat. The lowest starting dosage of rosuvastatin is recommended, then titrated as needed based on clinical response and tolerance. According to some authorities, the dose of rosuvastatin should not exceed 10 mg daily. All patients receiving statin therapy should be advised to promptly report any unexplained muscle pain, tenderness or weakness, particularly if accompanied by fever, malaise and/or dark colored urine. Therapy should be discontinued if creatine kinase is markedly elevated in the absence of strenuous exercise or if myopathy is otherwise suspected or diagnosed.

GENERALLY AVOID: Cobicistat may increase the plasma concentrations of antiretroviral agents. The plasma concentrations of cobicistat may also be increased or reduced in the presence of antiretroviral agents. The proposed mechanism is cobicistat inhibition of the CYP450 3A4 isoenzyme, of which antiretroviral agents may be substrates, and the inhibition or induction of CYP450 3A4 by concomitant antiretroviral medications. Cobicistat is a mechanism-based inhibitor and substrate of CYP450 3A4 with no antiretroviral activity of its own. Rather, it is indicated in its capacity as a pharmacokinetic booster of CYP450 3A4 to increase the systemic exposure of some antiretroviral medications such as atazanavir, darunavir, and elvitegravir, which are substrates of this isoenzyme. Concomitant use of other antiretroviral agents with cobicistat may also increase the plasma levels and risk of side effects associated with these medicines. In contrast, concomitant use of cobicistat-boosted atazanavir or darunavir with CYP450 3A4 inducers nevirapine, etravirine, or efavirenz may reduce the plasma concentrations of cobicistat, darunavir, and atazanavir, leading to a potential loss of therapeutic effect and development of resistance to darunavir and atazanavir. Pharmacokinetic data are not available.

MANAGEMENT: Cobicistat is not intended for use with more than one antiretroviral medication that requires pharmacokinetic enhancement, such as two protease inhibitors or elvitegravir in combination with a protease inhibitor. In addition, cobicistat should not be used concomitantly with ritonavir due to their similar effects on CYP450 3A4. According to some authorities, use of the antiretroviral combinations of atazanavir-cobicistat or darunavir-cobicistat concomitantly with the CYP450 3A4 inducers efavirenz, etravirine, or nevirapine is also not recommended. Other authorities consider the administration of atazanavir-cobicistat with efavirenz or nevirapine to be contraindicated. Since dosing recommendations have only been established for a number of antiretroviral medications, product labeling and current antiretroviral treatment guidelines should be consulted.