Abstract: SA-PO0588
A Case of Fanconi-Like Syndrome Associated with Tenofovir Alafenamide-Based HIV Pre-Exposure Prophylaxis (PrEP)
Session Information
- Fluid, Electrolyte, and Acid-Base Disorders: Case Reports - 2
October 24, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Fluid, Electrolytes, and Acid-Base Disorders
- 1102 Fluid, Electrolyte, and Acid-Base Disorders: Clinical
Authors
- Chandawarkar, Simran, Northeast Ohio Medical University, Rootstown, Ohio, United States
- Schroeder, Kevin, OhioHealth, Columbus, Ohio, United States
Introduction
Tenofovir-based pre-exposure prophylaxis (PrEP) is highly effective for prevention of HIV transmission. Although tenofovir alafenamide (TAF) was developed to reduce the nephrotoxicity associated with tenofovir disoproxil fumarate, rare cases of proximal tubular dysfunction and Fanconi syndrome continue to be reported. Early recognition of drug-induced Fanconi syndrome is essential to prevent severe metabolic complications and irreversible renal injury.
Case Description
A 30-year-old transgender male on emtricitabine/tenofovir alafenamide (TAF) for HIV PrEP presented with three weeks of nausea, vomiting, and poor oral intake. Medical history included Tourette’s disorder, migraines, depression, autism, and fibromyalgia. Home medications included topiramate, rosuvastatin, and testosterone gel. Laboratory evaluation demonstrated anion gap metabolic acidosis, acute kidney injury, elevated creatine kinase, hypokalemia, hypomagnesemia, and hypophosphatemia. Urinalysis showed proteinuria, ketonuria, and hematuria. Initial management with intravenous fluids for presumed rhabdomyolysis failed to improve the patient’s worsening acidemia and electrolyte wasting. Persistent metabolic derangements with evidence of proximal tubular dysfunction raised concern for Fanconi-like syndrome. TAF, testosterone, and topiramate were discontinued, and the patient was treated with bicarbonate infusion and aggressive electrolyte replacement. Renal function and metabolic abnormalities resolved prior to discharge.
Discussion
This case demonstrates a rare but clinically significant presentation of TAF-associated Fanconi-like syndrome. While TAF is generally considered safer than earlier tenofovir formulations, clinically important proximal tubular toxicity can still occur. The uniqueness of this case lies in the severe metabolic derangements occurring in the setting of multiple concurrent renal stressors, including dehydration and rhabdomyolysis, which may have potentiated tubular injury. Clinical findings included profound electrolyte wasting, metabolic acidosis, proteinuria, and acute kidney injury with improvement after withdrawal of TAF. The key teaching point is that clinicians should maintain a high index of suspicion for PrEP-associated Fanconi syndrome in patients presenting with otherwise unexplained metabolic acidosis and electrolyte abnormalities, even when using newer tenofovir formulations marketed as renally safer.