Ledipasvir and sofosbuvir

Coadministration with amiodarone may result in serious symptomatic bradycardia. Use of ledipasvir and sofosbuvir with amiodarone is not recommended. ( 5.2 , 6.2 , 7.2 ) P-gp inducers (e.g., rifampin, St. John's wort): May alter concentrations of ledipasvir and sofosbuvir. Use of ledipasvir and sofosbuvir with P-gp inducers is not recommended. ( 5.3 , 7 , 12.3 ) Consult the full prescribing information prior to use for potential drug interactions. ( 5.2 , 5.3 , 7 , 12.3 ) Clearance of HCV infection with direct acting antivirals may lead to changes in hepatic function, which may impact safe and effective use of concomitant medications.

Frequent monitoring of relevant laboratory parameters (INR or blood glucose) and dose adjustments of certain concomitant medications may be necessary. ( 7.2 )

7.1 Potential for Drug Interaction Any interactions that have been identified with ledipasvir or sofosbuvir individually may occur with ledipasvir and sofosbuvir. After oral administration of ledipasvir and sofosbuvir, sofosbuvir is rapidly absorbed and subject to extensive first-pass hepatic extraction. In clinical pharmacology studies, both sofosbuvir and the inactive metabolite GS-331007 were monitored for purposes of pharmacokinetic analyses. Ledipasvir is an inhibitor of the drug transporters P-gp and breast cancer resistance protein (BCRP) and may increase intestinal absorption of coadministered substrates for these transporters.

Ledipasvir and sofosbuvir are substrates of drug transporters P-gp and BCRP while GS-331007 is not. P-gp inducers (e.g., rifampin, St. John's wort) may decrease ledipasvir and sofosbuvir plasma concentrations, leading to reduced therapeutic effect of ledipasvir and sofosbuvir, and the use with P-gp inducers is not recommended with ledipasvir and sofosbuvir [see Warnings and Precautions (5.3) ] .

7.2 Established and Potentially Significant Drug Interactions Clearance of HCV infection with direct acting antivirals may lead to changes in hepatic function, which may impact the safe and effective use of concomitant medications. For example, altered blood glucose control resulting in serious symptomatic hypoglycemia has been reported in diabetic patients in postmarketing case reports and published epidemiological studies. Management of hypoglycemia in these cases required either discontinuation or dose modification of concomitant medications used for diabetes treatment.

Frequent monitoring of relevant laboratory parameters (e.g., International Normalized Ratio [INR] in patients taking warfarin, blood glucose levels in diabetic patients) or drug concentrations of concomitant medications such as cytochrome P450 substrates with a narrow therapeutic index (e.g., certain immunosuppressants) is recommended to ensure safe and effective use. Dose adjustments of concomitant medications may be necessary. Table 6 provides a listing of established or potentially clinically significant drug interactions.

The drug interactions described are based on studies conducted with either ledipasvir and sofosbuvir tablets (90 mg/400 mg) or ledipasvir and sofosbuvir as individual agents, or are predicted drug interactions that may occur with ledipasvir and sofosbuvir [see Warnings and Precautions (5.2 , 5.3) and Clinical Pharmacology (12.3) ] . Table 6 Potentially Significant Drug Interactions: Alteration in Dose or Regimen May Be Recommended Based on Drug Interaction Studies or Predicted Interaction This table is not all inclusive.

Concomitant Drug Class: Drug Name Effect on Concentration ↓ = decrease, ↑ = increase Clinical Comment tenofovir DF = tenofovir disoproxil fumarate Acid Reducing Agents: ↓ ledipasvir Ledipasvir solubility decreases as pH increases. Drugs that increase gastric pH are expected to decrease concentration of ledipasvir. Antacids (e.g., aluminum and magnesium hydroxide) It is recommended to separate antacid and ledipasvir and sofosbuvir administration by 4 hours. H 2 -receptor antagonists These interactions have been studied in healthy adults.

(e.g., famotidine) H 2 -receptor antagonists may be administered simultaneously with or 12 hours apart from ledipasvir and sofosbuvir at a dose that does not exceed doses comparable to famotidine 40 mg twice daily. Proton-pump inhibitors (e.g., omeprazole) Proton-pump inhibitor doses comparable to omeprazole 20 mg or lower can be administered simultaneously with ledipasvir and sofosbuvir under fasted conditions. Antiarrhythmics: amiodarone Effect on amiodarone, ledipasvir, and sofosbuvir concentrations unknown Coadministration of amiodarone with ledipasvir and sofosbuvir may result in serious symptomatic bradycardia. The mechanism of this effect is unknown.

Coadministration of amiodarone with ledipasvir and sofosbuvir is not recommended; if coadministration is required, cardiac monitoring is recommended [see Warnings and Precautions (5.2) , Adverse Reactions (6.2) ]. digoxin ↑ digoxin Coadministration of ledipasvir and sofosbuvir with digoxin may increase the concentration of digoxin. Therapeutic concentration monitoring of digoxin is recommended when coadministered with ledipasvir and sofosbuvir.

Anticonvulsants: carbamazepine phenytoin phenobarbital ↓ ledipasvir ↓ sofosbuvir Coadministration of ledipasvir and sofosbuvir with carbamazepine, phenytoin, or phenobarbital is expected to decrease the concentration of ledipasvir and sofosbuvir, leading to reduced therapeutic effect of ledipasvir and sofosbuvir. Coadministration is not recommended. Antimycobacterials: rifabutin rifampin rifapentine ↓ ledipasvir ↓ sofosbuvir Coadministration of ledipasvir and sofosbuvir with rifampin, rifabutin, or rifapentine is not recommended [see Warnings and Precautions (5.3) ].

HIV Antiretrovirals: Regimens containing tenofovir DF without an HIV protease inhibitor/ritonavir or cobicistat ↑ tenofovir Monitor for tenofovir-associated adverse reactions in patients receiving ledipasvir and sofosbuvir concomitantly with a regimen containing tenofovir DF without an HIV protease inhibitor/ritonavir or cobicistat. Refer to Viread ® or Truvada ® prescribing information for recommendations on renal monitoring.

Regimens containing tenofovir DF and an HIV protease inhibitor/ritonavir or cobicistat atazanavir/ritonavir or cobicistat + emtricitabine/tenofovir DF darunavir/ritonavir or cobicistat + emtricitabine/tenofovir DF lopinavir/ritonavir + emtricitabine/tenofovir DF ↑ tenofovir The safety of increased tenofovir concentrations in the setting of ledipasvir and sofosbuvir and an HIV protease inhibitor/ritonavir or cobicistat has not been established. Consider alternative HCV or antiretroviral therapy to avoid increases in tenofovir exposures. If coadministration is necessary, monitor for tenofovir-associated adverse reactions.

Refer to Viread or Truvada prescribing information for recommendations on renal monitoring. elvitegravir, cobicistat, emtricitabine, tenofovir DF ↑ tenofovir The safety of increased tenofovir concentrations in the setting of ledipasvir and sofosbuvir and the combination of elvitegravir, cobicistat, emtricitabine, and tenofovir DF has not been established. Coadministration is not recommended. tipranavir/ritonavir ↓ ledipasvir ↓ sofosbuvir Coadministration of ledipasvir and sofosbuvir with tipranavir/ritonavir is expected to decrease the concentration of ledipasvir and sofosbuvir, leading to reduced therapeutic effect of ledipasvir and sofosbuvir. Coadministration is not recommended.

HCV Products: simeprevir ↑ ledipasvir ↑ simeprevir Concentrations of ledipasvir and simeprevir are increased when simeprevir is coadministered with ledipasvir. Coadministration of ledipasvir and sofosbuvir with simeprevir is not recommended. Herbal Supplements: St. John's wort (Hypericum perforatum) ↓ ledipasvir ↓ sofosbuvir Coadministration of ledipasvir and sofosbuvir with St. John's wort, a P-gp inducer, is not recommended [see Warnings and Precautions (5.3) ].

HMG-CoA Reductase Inhibitors: rosuvastatin ↑ rosuvastatin Coadministration of ledipasvir and sofosbuvir with rosuvastatin may significantly increase the concentration of rosuvastatin, which is associated with increased risk of myopathy, including rhabdomyolysis. Coadministration of ledipasvir and sofosbuvir with rosuvastatin is not recommended. atorvastatin ↑ atorvastatin Coadministration of ledipasvir and sofosbuvir with atorvastatin may be associated with increased risk of myopathy, including rhabdomyolysis. Monitor closely for HMG-CoA reductase inhibitor-associated adverse reactions, such as myopathy and rhabdomyolysis.

7.3 Drugs without Clinically Significant Interactions with Ledipasvir and Sofosbuvir Based on drug interaction studies conducted with ledipasvir, sofosbuvir, or ledipasvir and sofosbuvir tablets (90 mg/400 mg) no clinically significant drug interactions have been either observed or are expected when ledipasvir and sofosbuvir is used with the following drugs [see Clinical Pharmacology (12.3) ]: abacavir, atazanavir/ritonavir,…

8.1 Pregnancy Risk Summary If ledipasvir and sofosbuvir is administered with ribavirin, the combination regimen is contraindicated in pregnant women and in men whose female partners are pregnant. Refer to the ribavirin prescribing information for more information on ribavirin-associated risks of use during pregnancy. No adequate human data are available to establish whether or not ledipasvir and sofosbuvir pose a risk to pregnancy outcomes. In animal reproduction studies, no evidence of adverse developmental outcomes was observed with ledipasvir or sofosbuvir at exposures greater than those in humans at the recommended human dose (RHD) [see Data ] .

During organogenesis in the rat and rabbit, systemic exposures (AUC) to ledipasvir were approximately 4 (rats) and 2 (rabbits) times the exposure in humans at the RHD, while exposures to the predominant circulating metabolite of sofosbuvir (GS-331007) were ≥3 (rats) and 7 (rabbits) times the exposure in humans at the RHD. In rat pre/postnatal development studies, maternal systemic exposures (AUC) to ledipasvir and GS-331007 were approximately 5 and 7 times, respectively, the exposure in humans at the RHD. The background risk of major birth defects and miscarriage for the indicated population is unknown. In the U.S.

general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2–4% and 15–20%, respectively. Data Animal Data Ledipasvir: Ledipasvir was administered orally to pregnant rats (up to 100 mg/kg/day) and rabbits (up to 180 mg/kg/day) on gestation days 6 to 18 and 7 to 20, respectively, and also to rats (oral doses up to 100 mg/kg/day) on gestation day 6 to lactation/post-partum day 20. No significant effects on embryo-fetal (rats and rabbits) or pre/postnatal (rats) development were observed at the highest doses tested. Systemic exposures (AUC) to ledipasvir were ≥4 (rats) and 2 (rabbits) times the exposure in humans at the RHD.

Sofosbuvir: Sofosbuvir was administered orally to pregnant rats (up to 500 mg/kg/day) and rabbits (up to 300 mg/kg/day) on gestation days 6 to 18 and 6 to 19, respectively, and also to rats (oral doses up to 500 mg/kg/day) on gestation day 6 to lactation/post-partum day 20. No significant effects on embryo-fetal (rats and rabbits) or pre/postnatal (rats) development were observed at the highest doses tested. Systemic exposures (AUC) to the predominant circulating metabolite of sofosbuvir (GS-331007) were ≥3 (rats) and 7 (rabbits) times the exposure in humans at the RHD, with exposures increasing during…