BICTEGRAVIR Drug Interactions: What You Need to Know

INTERACTIONS Because BIKTARVY is a complete regimen, coadministration with other antiretroviral medications for the treatment of HIV-1 infection is not recommended. ( 7.1 ) Consult the Full Prescribing Information prior to and during treatment for important drug interactions. ( 4 , 5.2 , 7 , 12.3 )

7.1 Other Antiretroviral Medications Because BIKTARVY is a complete regimen, coadministration with other antiretroviral medications for the treatment of HIV-1 infection is not recommended <span class="opacity-50 text-xs">[see Indications and Usage (1) ]</span> . Comprehensive information regarding potential drug-drug interactions with other antiretroviral medications is not provided because the safety and efficacy of concomitant HIV-1 antiretroviral therapy is unknown.

7.2 Potential for BIKTARVY to Affect Other Drugs BIC inhibits organic cation transporter 2 (OCT2) and multidrug and toxin extrusion transporter 1 (MATE1) in vitro . Coadministration of BIKTARVY with drugs that are substrates of OCT2 and MATE1 (e.g., dofetilide) may increase their plasma concentrations (see Table 3 ).

7.3 Potential Effect of Other Drugs on One or More Components of BIKTARVY BIC is a substrate of CYP3A and UGT1A1. A drug that is a strong inducer of CYP3A and also an inducer of UGT1A1 can substantially decrease the plasma concentrations of BIC which may lead to loss of therapeutic effect of BIKTARVY and development of resistance <span class="opacity-50 text-xs">[see Clinical Pharmacology (12.3) ]</span> . The use of BIKTARVY with a drug that is a strong inhibitor of CYP3A and also an inhibitor of UGT1A1 may significantly increase the plasma concentrations of BIC. TAF is a substrate of P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP). Co-administration of drugs that inhibit P-gp and BCRP may increase the absorption and plasma concentrations of TAF <span class="opacity-50 text-xs">[see Clinical Pharmacology (12.3) ]</span> . Co-administration of drugs that induce P-gp activity are expected to decrease the absorption of TAF, resulting in decreased plasma concentration of TAF, which may lead to loss of therapeutic effect of BIKTARVY and development of resistance (see Table 3 ).

7.4 Drugs Affecting Renal Function Because FTC and tenofovir are primarily excreted by the kidneys by a combination of glomerular filtration and active tubular secretion, coadministration of BIKTARVY with drugs that reduce renal function or compete for active tubular secretion may increase concentrations of FTC, tenofovir, and other renally eliminated drugs and this may increase the risk of adverse reactions. Some examples of drugs that are eliminated by active tubular secretion include, but are not limited to, acyclovir, cidofovir, ganciclovir, valacyclovir, valganciclovir, aminoglycosides (e.g., gentamicin), and high-dose or multiple NSAIDs <span class="opacity-50 text-xs">[see Warnings and Precautions (5.4) ]</span> .

7.5 Established and Potentially Significant Drug Interactions Table 3 provides a listing of established or potentially clinically significant drug interactions with recommended prevention or management strategies. The drug interactions described are based on studies conducted with either BIKTARVY, the components of BIKTARVY (BIC, FTC, and TAF) as individual agents, or are drug interactions that may occur with BIKTARVY <span class="opacity-50 text-xs">[see Contraindications (4) , Warnings and Precautions (5.2) , and Clinical Pharmacology (12.3) ]</span> .

Table

3 Established and Potentially Significant Table is not all inclusive.

Drug

Interactions: Alteration in Regimen May be Recommended Concomitant Drug Class: Drug Name Effect on Concentration ↑ = Increase, ↓ = Decrease.

Clinical Comment

Antiarrhythmics: dofetilide ↑ Dofetilide Coadministration is contraindicated due to the potential for serious and/or life-threatening events associated with dofetilide therapy [see Contraindications (4) ] . Anticonvulsants: carbamazepine Drug-drug interaction study was conducted with either BIKTARVY or its components as individual agents. oxcarbazepine phenobarbital phenytoin ↓ BIC ↓ TAF Coadministration with alternative anticonvulsants should be considered. Antimycobacterials: rifabutin rifampin , Strong inducer of CYP3Aand P-gp, and inducer of UGT1A1. rifapentine ↓ BIC ↓ TAF Coadministration with rifampin is contraindicated due to the effect of rifampin on the BIC component of BIKTARVY [see Contraindications (4) ] . Coadministration with rifabutin or rifapentine is not recommended.

Herbal

Products: St. John’s wort The induction potency of St. John’s wort may vary widely based on preparation. ↓ BIC ↓ TAF Coadministration with St. John’s wort is not recommended. Oral medications or supplements containing polyvalent cations (e.g., Mg, Al, Ca, Fe): Calcium or iron supplements Cation-containing antacids or laxatives Sucralfate Buffered medications ↓ BIC Antacids containing Al/Mg: BIKTARVY can be taken at least 2 hours before or 6 hours after taking antacids containing Al/Mg. Routine administration of BIKTARVY together with, or 2 hours after, antacids containing Al/Mg is not recommended. Supplements or Antacids containing Calcium or Iron: BIKTARVY and supplements or antacids containing calcium or iron can be taken together with food. Routine administration of BIKTARVY under fasting conditions together with, or 2 hours after, supplements or antacids containing calcium or iron is not recommended. In pregnant individuals: Antacids containing Al/Mg: BIKTARVY can be taken at least 2 hours before or 6 hours after antacids containing Al/Mg regardless of food intake. Supplements or Antacids containing Calcium or Iron: BIKTARVY and supplements or antacids containing calcium or iron can be taken together with food; but when taken on an empty stomach, BIKTARVY should be taken at least 2 hours before or 6 hours after supplements or antacids containing calcium or iron. Metformin ↑ Metformin Refer to the prescribing information of metformin for assessing the benefit and risk of concomitant use of BIKTARVY and metformin.

7.6 Drugs without Clinically Significant Interactions with BIKTARVY Based on drug interaction studies conducted with BIKTARVY or the components of BIKTARVY, no clinically significant drug interactions have been observed when BIKTARVY is combined with the following drugs: ethinyl estradiol, ledipasvir/sofosbuvir, midazolam, norgestimate, sertraline, sofosbuvir, sofosbuvir/velpatasvir, and sofosbuvir/velpatasvir/voxilaprevir.

BIKTARVY is contraindicated to be co-administered with: dofetilide due to the potential for increased dofetilide plasma concentrations and associated serious and/or life-threatening events [see Drug Interactions (7.5) ] . rifampin due to decreased BIC plasma concentrations, which may result in the loss of therapeutic effect and development of resistance to BIKTARVY [see Drug Interactions (7.5) ] . BIKTARVY is contraindicated to be co-administered with: dofetilide. ( 4 ) rifampin. ( 4 )

AND PRECAUTIONS Immune reconstitution syndrome: May necessitate further evaluation and treatment. ( 5.3 ) New onset or worsening renal impairment: Assess serum creatinine, estimated creatinine clearance, urine glucose and urine protein when initiating BIKTARVY and during therapy as clinically appropriate in all patients. Also assess serum phosphorus in patients with chronic kidney disease. ( 5.4 ) Lactic acidosis/severe hepatomegaly with steatosis: Discontinue treatment in patients who develop symptoms or laboratory findings suggestive of lactic acidosis or pronounced hepatotoxicity. ( 5.5 )

5.1 Severe Acute Exacerbation of Hepatitis B in Patients Coinfected with HIV-1 and HBV Patients with HIV-1 should be tested for the presence of chronic hepatitis B virus (HBV) infection before or when initiating antiretroviral therapy <span class="opacity-50 text-xs">[see Dosage and Administration (2.1) ]</span> . Severe acute exacerbations of hepatitis B (e.g., liver decompensation and liver failure) have been reported in patients who are coinfected with HIV-1 and HBV and have discontinued products containing FTC and/or tenofovir disoproxil fumarate (TDF), and may occur with discontinuation of BIKTARVY. Patients coinfected with HIV-1 and HBV who discontinue BIKTARVY should be closely monitored with both clinical and laboratory follow-up for at least several months after stopping treatment. If appropriate, anti-hepatitis B therapy may be warranted, especially in patients with advanced liver disease or cirrhosis, since post-treatment exacerbation of hepatitis may lead to hepatic decompensation and liver failure.

5.2 Risk of Adverse Reactions or Loss of Virologic Response Due to Drug Interactions The concomitant use of BIKTARVY with certain other drugs may result in known or potentially significant drug interactions, some of which may lead to <span class="opacity-50 text-xs">[see Contraindications (4) , and Drug Interactions (7.5) ]</span>: Loss of therapeutic effect of BIKTARVY and possible development of resistance. Possible clinically significant adverse reactions from greater exposures of concomitant drugs.

See Table

3 for steps to prevent or manage these possible and known significant drug interactions, including dosing recommendations. Consider the potential for drug interactions prior to and during BIKTARVY therapy; review concomitant medications during BIKTARVY therapy; and monitor for the adverse reactions associated with the concomitant drugs.

5.3 Immune Reconstitution Syndrome Immune reconstitution syndrome has been reported in patients treated with combination antiretroviral therapy. During the initial phase of combination antiretroviral treatment, patients whose immune system responds may develop an inflammatory response to indolent or residual opportunistic infections [such as Mycobacterium avium infection, cytomegalovirus, Pneumocystis jirovecii pneumonia (PCP), or tuberculosis], which may necessitate further evaluation and treatment. Autoimmune disorders (such as Graves&apos; disease, polymyositis, Guillain-Barré syndrome, and autoimmune hepatitis) have also been reported to occur in the setting of immune reconstitution; however, the time to onset is more variable, and can occur many months after initiation of treatment.

5.4 New Onset or Worsening Renal Impairment Postmarketing cases of renal impairment, including acute renal failure, proximal renal tubulopathy (PRT), and Fanconi syndrome, have been reported with TAF-containing products; while most of these cases were characterized by potential confounders that may have contributed to the reported renal events, it is also possible these factors may have predisposed patients to tenofovir-related adverse events <span class="opacity-50 text-xs">[see Adverse Reactions (6.1 , 6.2) ]</span>. BIKTARVY is not recommended in patients with severe renal impairment (estimated creatinine clearance of 15 to below 30 mL/min), or patients with ESRD (estimated creatinine clearance below 15 mL/min) who are not receiving chronic hemodialysis, or patients with no antiretroviral treatment history and ESRD who are receiving chronic hemodialysis <span class="opacity-50 text-xs">[see Dosage and Administration (2.4) , and Use in Specific Populations (8.6) ]</span> . Patients taking tenofovir prodrugs who have impaired renal function and those taking nephrotoxic agents including non-steroidal anti-inflammatory drugs are at increased risk of developing renal-related adverse reactions. Prior to or when initiating BIKTARVY, and during treatment with BIKTARVY, assess serum creatinine, estimated creatinine clearance, urine glucose and urine protein in all patients as clinically appropriate. In patients with chronic kidney disease, also assess serum phosphorus. Discontinue BIKTARVY in patients who develop clinically significant decreases in renal function or evidence of Fanconi syndrome.

5.5 Lactic Acidosis/Severe Hepatomegaly with Steatosis Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogs, including emtricitabine, a component of BIKTARVY, and tenofovir DF, another prodrug of tenofovir, alone or in combination with other antiretrovirals. Treatment with BIKTARVY should be suspended in any patient who develops clinical or laboratory findings suggestive of lactic acidosis or pronounced hepatotoxicity (which may include hepatomegaly and steatosis even in the absence of marked transaminase elevations).