Biktarvy Renal Contraindications
Biktarvy is not recommended in patients with estimated creatinine clearance of 15 to below 30 mL/min, or below 15 mL/min who are not receiving chronic hemodialysis, or below 15 mL/min who have no antiretroviral treatment history. 1
Specific Creatinine Clearance Thresholds
Absolute Contraindications
- CrCl 15 to <30 mL/min: Biktarvy is not recommended for any patient in this range 1
- CrCl <15 mL/min without chronic hemodialysis: Biktarvy is not recommended 1
- CrCl <15 mL/min with no antiretroviral treatment history: Biktarvy is not recommended even if receiving chronic hemodialysis 1
Special Exception for Hemodialysis
- CrCl <15 mL/min on chronic hemodialysis AND virologically-suppressed: Biktarvy may be used at standard dosing (50 mg BIC/200 mg FTC/25 mg TAF once daily) only in this specific population 1
Rationale for Renal Restrictions
The renal limitations stem from the emtricitabine and tenofovir alafenamide components of Biktarvy. Emtricitabine requires dose adjustment when CrCl falls below 50 mL/min (every 48 hours for CrCl 30-49 mL/min, every 72 hours for CrCl 15-29 mL/min, every 96 hours for CrCl <15 mL/min) 2. Since Biktarvy is a fixed-dose combination tablet, these individual component adjustments cannot be made, necessitating avoidance of the medication in moderate to severe renal impairment 1.
Monitoring Requirements
Prior to initiating Biktarvy and during treatment, assess serum creatinine, estimated creatinine clearance, urine glucose, and urine protein in all patients. 1 In patients with chronic kidney disease, also assess serum phosphorus 1.
Tenofovir Alafenamide vs. Tenofovir Disoproxil Fumarate
Tenofovir alafenamide (TAF, the component in Biktarvy) has improved renal safety compared to tenofovir disoproxil fumarate (TDF), but still requires caution in renal impairment 2. TAF is not recommended in patients with CrCl below 30 mL/min 2. In contrast, TDF should be avoided or dose-adjusted in patients with CrCl below 60 mL/min 2.
Clinical Pitfalls
- Do not confuse the CrCl <15 mL/min threshold: The exception for chronic hemodialysis patients only applies to those who are virologically-suppressed; treatment-naïve patients on dialysis cannot receive Biktarvy 1
- Monitor for declining renal function: Postmarketing cases of renal impairment, including acute renal failure and proximal renal tubulopathy, have been reported with TAF-containing products 1
- Discontinue if renal function worsens: Stop Biktarvy in patients who develop clinically significant decreases in renal function or evidence of Fanconi syndrome 1