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BOXED WARNING: LACTIC ACIDOSIS/SEVERE HEPATOMEGALY WITH STEATOSIS and POST TREATMENT ACUTE EXACERBATION OF HEPATITIS B

• Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogs, including tenofovir disoproxil fumarate (tenofovir DF), a component of STRIBILD, in combination with other antiretrovirals.
• STRIBILD is not approved for the treatment of chronic hepatitis B virus (HBV) infection and the safety and efficacy of STRIBILD have not been established in patients coinfected with HBV and HIV-1. Severe acute exacerbations of hepatitis B have been reported in patients who are coinfected with HBV and HIV-1 and have discontinued emtricitabine or tenofovir DF, components of STRIBILD. Hepatic function should be monitored closely with both clinical and laboratory follow-up for at least several months in patients who are coinfected with HIV-1 and HBV and discontinue STRIBILD. If appropriate, initiation of anti-hepatitis B therapy may be warranted.

Contraindications

• Coadministration: Do not use with drugs highly dependent on CYP3A for clearance and for which elevated plasma concentrations are associated with serious and/or life-threatening events. Do not use with drugs that strongly induce CYP3A as this may lead to loss of efficacy and possible resistance to STRIBILD. Use with the following drugs is contraindicated: alfuzosin, rifampin, dihydroergotamine, ergotamine, methylergonovine, cisapride, lovastatin, simvastatin, pimozide, sildenafil for pulmonary arterial hypertension, triazolam, oral midazolam, and St. John’s wort.

Warnings and precautions

• New onset or worsening renal impairment: Cases of acute renal failure and Fanconi syndrome have been reported with the use of tenofovir DF and STRIBILD. In all patients, monitor estimated creatinine clearance (CrCl), urine glucose, and urine protein prior to initiating and during therapy. In patients with or at risk for renal impairment, additionally monitor serum phosphorus. Do not initiate STRIBILD in patients with CrCl <70 mL/min. Discontinue STRIBILD if CrCl declines to <50 mL/min. Cobicistat may cause modest increases in serum creatinine and modest declines in CrCl without affecting renal glomerular function; patients with an increase in serum creatinine >0.4 mg/dL from baseline should be closely monitored for renal safety. Avoid concurrent or recent use with a nephrotoxic agent. Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after initiation of high dose or multiple NSAIDs in patients with risk factors for renal dysfunction; consider alternatives to NSAIDs in these patients. Persistent or worsening bone pain, pain in extremities, fractures and/or muscular pain or weakness may be manifestations of proximal renal tubulopathy and should prompt an evaluation of renal function.
• Other antiretroviral products: STRIBILD is a complete regimen for the treatment of HIV-1 infection. Do not coadminister with other antiretroviral products, including products containing any of the same active components; products containing lamivudine; products containing ritonavir; or with adefovir dipivoxil.
• Bone effects: Decreases in bone mineral density (BMD) and mineralization defects, including osteomalacia, have been seen in patients treated with tenofovir DF. Consider monitoring BMD in patients with a history of pathologic fracture or risk factors for bone loss. In patients at risk of renal dysfunction who present with persistent or worsening bone or muscle symptoms, hypophosphatemia and osteomalacia secondary to proximal renal tubulopathy should be considered
• Fat redistribution and accumulation have been observed in patients receiving antiretroviral therapy.
• Immune reconstitution syndrome, including the occurrence of autoimmune disorders with variable time to onset, has been reported.

Adverse reactions

• Common adverse drug reactions in clinical studies (incidence >5%; all grades) were nausea (16%), diarrhea (12%), abnormal dreams (9%), and headache (7%).

Drug interactions

• CYP3A substrates: STRIBILD can alter the concentration of drugs metabolized by CYP3A or CYP2D6. Do not use with drugs highly dependent on these factors for clearance and for which elevated plasma concentrations are associated with serious and/or life-threatening adverse events.
• CYP3A inducers: Drugs that induce CYP3A can decrease the concentrations of components of STRIBILD. Do not use with drugs that strongly induce CYP3A as this may lead to loss of efficacy and possible resistance to STRIBILD.
• Drugs affecting renal function: Coadministration of STRIBILD with drugs that reduce renal function or compete for active tubular secretion may increase concentrations of emtricitabine and tenofovir and the risk of adverse reactions.
• Antacids: Separate STRIBILD and antacid administration by at least 2 hours.
• Prescribing information: Consult the full Prescribing Information for STRIBILD for more information on potentially significant drug interactions, including clinical comments.

Dosage and administration

• Adult dosage: One tablet taken orally once daily with food.
• Renal impairment: Do not initiate in patients with CrCl below 70 mL/min. Discontinue in patients with CrCl below 50 mL/min.
• Hepatic impairment: Not recommended in patients with severe hepatic impairment.
• Testing prior to initiation: Test patients for HBV infection and document baseline CrCl, urine glucose, and urine protein.

Pregnancy and breastfeeding

• Pregnancy Category B: There are no adequate and well-controlled studies in pregnant women. Use during pregnancy only if the potential benefit justifies the potential risk. An Antiretroviral Pregnancy Registry has been established.
• Breastfeeding: Emtricitabine and tenofovir have been detected in human milk. Because of both the potential for HIV transmission and the potential for serious adverse reactions in nursing infants, mothers should be instructed not to breastfeed.

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