Tenofovir Dosage for HIV-Infected Adults/Adolescents with Normal Renal Function
For HIV treatment in adults and adolescents with normal kidney function (creatinine clearance ≥50 mL/min), the standard dose of tenofovir disoproxil fumarate (TDF) is 300 mg orally once daily, with no dosage adjustment required. 1, 2
Standard Dosing for HIV Treatment
The recommended dose is tenofovir disoproxil fumarate 300 mg once daily for patients with creatinine clearance ≥50 mL/min 1, 2
No adjustment is needed for normal renal function, defined as creatinine clearance ≥50 mL/min 1
Food enhances bioavailability by approximately 40% (AUC) when taken with high-fat meals, though steady-state exposure is similar with or without typical meals 2, 3
The drug can be taken with or without food in clinical practice, as steady-state pharmacokinetics are comparable 2
Dosage Adjustments for Renal Impairment
While your question specifies normal kidney function, understanding the renal dosing thresholds is critical since tenofovir is nephrotoxic:
Creatinine clearance 30-49 mL/min: 300 mg every 48 hours 1, 2
Creatinine clearance 10-29 mL/min: 300 mg every 72-96 hours 1, 2
Hemodialysis patients: 300 mg every 7 days after dialysis session 1, 2
No adjustment needed for hepatic impairment of any severity 1, 2, 4
Critical Monitoring Requirements
Before initiating tenofovir, mandatory baseline testing includes:
- Combined HIV antibody/antigen test 5
- Serum creatinine and estimated creatinine clearance 5, 2
- Hepatitis B surface antigen (critical - see caveat below) 5
- Hepatitis C antibody 5
- STI screening 5
During treatment, monitor:
- Renal function monitoring is essential even with normal baseline function, as tenofovir can cause progressive nephrotoxicity 1
- Creatinine clearance should be checked at baseline, 2-4 weeks after initiation, and then every 3-6 months 1
- More frequent monitoring (every 1-2 weeks) if risk factors present: baseline renal dysfunction, concurrent nephrotoxic drugs, or advanced HIV disease 1
Important Drug Interactions
Two medications require dosage modifications when co-administered with tenofovir:
- Didanosine: Requires dose reduction due to increased didanosine exposure 5, 3
- Atazanavir: Tenofovir clearance decreases by 23.5% when used with atazanavir/ritonavir, though standard tenofovir dosing is typically maintained with enhanced monitoring 5, 6
No dosage adjustment needed for other antiretrovirals, as tenofovir is not a substrate, inducer, or inhibitor of cytochrome P450 enzymes 2, 3
Critical Clinical Caveat: Hepatitis B Co-infection
Patients with chronic HBV must continue tenofovir indefinitely if switching HIV regimens, as discontinuation risks severe hepatitis flare or hepatic decompensation 5
This is a life-threatening complication that occurs because tenofovir suppresses HBV replication, and abrupt withdrawal can trigger immune-mediated liver injury.
Alternative Formulation: Tenofovir Alafenamide (TAF)
For specific populations, tenofovir alafenamide 25 mg (as part of combination products) once daily is an alternative that achieves similar efficacy with lower systemic tenofovir exposure 5, 7
TAF is preferred over TDF for patients with:
- Creatinine clearance 30-60 mL/min 5, 7
- Osteopenia or osteoporosis 5, 7
- Concerns about long-term bone or renal toxicity 7
Pharmacokinetic Considerations
- Terminal elimination half-life is approximately 17 hours, supporting once-daily dosing 2, 3
- Intracellular half-life exceeds 60 hours, providing forgiveness for occasional missed doses 3
- Steady-state is achieved within 5-7 days of daily dosing 2
- Approximately 70-80% is eliminated unchanged in urine via glomerular filtration and active tubular secretion 2, 4