What is the prep treatment for a patient with impaired renal function (Creatinine Clearance (CrCL) of 15ml/min)?

PrEP Treatment for Creatinine Clearance of 15 mL/min

PrEP (pre-exposure prophylaxis for HIV) is contraindicated at a creatinine clearance of 15 mL/min, and alternative prevention strategies must be employed.

Why PrEP Cannot Be Used at CrCl 15 mL/min

Tenofovir-Based Regimens Are Not Safe

• Tenofovir alafenamide (TAF) is contraindicated when CrCl falls below 15 mL/min without dialysis 1
• Tenofovir disoproxil fumarate (TDF) is not recommended in patients with CrCl below 10 mL/min without renal replacement therapy 1
• At CrCl 15 mL/min, you are in the zone where both formulations carry unacceptable risks of further nephrotoxicity and drug accumulation 1

The Mechanism Problem

• Both tenofovir formulations undergo significant renal elimination, with TAF requiring CrCl ≥15 mL/min and TDF requiring CrCl ≥10 mL/min for any consideration of use 1, 2
• At CrCl 15 mL/min, you are at Stage 5 CKD (kidney failure), where drug accumulation and toxicity risks are prohibitively high 3

Alternative HIV Prevention Strategies

Non-Pharmacologic Prevention

• Consistent condom use remains the primary prevention method when PrEP is contraindicated
• Partner testing and treatment to achieve undetectable viral loads (U=U: undetectable equals untransmittable)
• Risk reduction counseling including safer sex practices and reduction of number of partners

If Dialysis Is Initiated

• TAF 25 mg once daily can be considered if the patient begins hemodialysis, administered following completion of dialysis 1
• This assumes three hemodialysis sessions per week of approximately 4 hours duration 1
• TDF 300 mg once weekly (or after approximately 12 hours of cumulative dialysis) is an alternative if on hemodialysis 1

Critical Monitoring at This Renal Function Level

Urgent Nephrology Involvement Required

• CrCl 15 mL/min requires urgent nephrology referral for renal replacement therapy planning 3
• Evaluate for life-threatening complications requiring emergency dialysis: severe hyperkalemia (K+ >6.5 mEq/L), pulmonary edema unresponsive to diuretics, severe metabolic acidosis (pH <7.2), or uremic symptoms 3

Medication Review Essential

• All renally cleared medications must be dose-adjusted or discontinued at this level of renal function 3, 2
• Avoid nephrotoxic agents including NSAIDs, aminoglycosides, and contrast dye 3

Common Pitfalls to Avoid

• Do not use standard PrEP dosing based on older guidelines that may not clearly specify the CrCl 15 mL/min threshold 1
• Do not rely on serum creatinine alone to assess renal function; calculate actual creatinine clearance using Cockcroft-Gault equation with ideal body weight 1
• Do not assume TAF is safe simply because it has better renal safety profile than TDF—both are contraindicated at CrCl 15 mL/min without dialysis 1, 2
• Do not delay nephrology referral while attempting to optimize HIV prevention—this patient needs renal replacement therapy planning immediately 3

The Bottom Line Algorithm

1. Confirm CrCl calculation using Cockcroft-Gault with ideal body weight 1
2. If CrCl truly ≤15 mL/min without dialysis: PrEP is contraindicated—use barrier methods and partner treatment strategies
3. If patient initiates hemodialysis: TAF 25 mg daily post-dialysis or TDF 300 mg weekly can be considered 1
4. Immediate nephrology referral for renal replacement therapy evaluation 3