Tenofovir Disoproxil Fumarate and Provenge Co-Administration

Mechanism and Pharmacology

• Tenofovir Disoproxil Fumarate (TDF) is a nucleotide reverse transcriptase inhibitor used for HIV treatment and prevention, as well as hepatitis B management, with a well-characterized pharmacokinetic profile 1, 2

Clinical Considerations for Co-Administration

• The National Comprehensive Cancer Network recommends monitoring renal function (serum creatinine, estimated GFR) as TDF can cause proximal renal tubular dysfunction, and assessing serum phosphate levels to detect tubular dysfunction 3, 4
• Consider switching to tenofovir alafenamide (TAF) if eGFR declines to <60 mL/min/1.73m² or shows rapid decline (>3-5 mL/min/1.73m² per year) 4

Special Populations

• The American Medical Association recommends immediate ART initiation for HIV-positive cancer patients, with attention to drug-drug interactions with chemotherapy agents (not Provenge specifically) 5

Common Pitfalls to Avoid

• The Journal of Hepatology notes that TDF interactions should not be confused with boosted regimens, as tenofovir levels increase by 25-37% when combined with ritonavir or cobicistat, raising nephrotoxicity risk 6
• The guideline society recommends not assuming all antiretrovirals behave similarly, as other antiretrovirals (particularly protease inhibitors with ritonavir/cobicistat boosting) may have different interaction profiles 7