Tenofovir disoproxil fumarate for COVID-19

Tenofovir disoproxil fumarate may be beneficial for COVID-19 according to the studies below. COVID-19 involves the interplay of 500+ viral and host proteins and factors providing many therapeutic targets. Scientists have proposed 11,000+ potential treatments. c19early.org analyzes 220+ treatments. We have not reviewed tenofovir disoproxil fumarate in detail.
Akinbolade et al., Repurposed Medicines for Viruses With Epidemic or Pandemic Potential: A Horizon Scan, Pharmacology Research & Perspectives, doi:10.1002/prp2.70271
ABSTRACT Viruses such as Ebola, Marburg, influenza, mpox, MERS‐CoV, SARS‐CoV, and SARS‐CoV‐2 may be considered pathogens of epidemic or pandemic concern. Developing novel antiviral medicines can be time‐consuming and resource intensive. Repurposing existing medicines with known or potential antiviral activity offers a faster, cost‐effective strategy to expand treatment options during public health emergencies. This scan aimed to map current investigational activity involving repurposed medicines for these viruses. A horizon scanning approach was employed, starting with a targeted search in Embase followed by a systematic search of ClinicalTrials.gov to identify developmental stages of relevant technologies. Eligible technologies included UK‐ or EU‐licensed medicines being investigated for antiviral use, while vaccines, unlicensed medicines, and treatments already approved for the target viruses were excluded. From the literature, 196 repurposed technologies were identified, and the expanded search on the clinical trials registry revealed 58 technologies in active clinical development. Interventional trial activity was limited to influenza and SARS‐CoV‐2, with 29 technologies for SARS‐CoV‐2 and two influenza technologies advancing to phase III evaluation. For other viruses, candidate repurposed technologies were identified only at preclinical or exploratory stages. Frequently investigated pharmacological classes included direct‐acting antivirals, immunomodulators, and anti‐inflammatory agents. While repurposing represents a potentially rapid strategy for therapeutic deployment, inclusion in this horizon scan does not imply clinical efficacy. Rigorous preclinical validation, pharmacokinetic feasibility assessment, and mechanistic confirmation remain essential before clinical translation.
Khaidarov et al., An Anti-HIV Drug Is Highly Effective Against SARS-CoV-2 In Vitro and Has Potential Benefit for Long COVID Treatment, Viruses, doi:10.3390/v17091170
The persistent evolution of SARS-CoV-2 necessitates novel antiviral strategies. This study evaluated the anti-HIV prodrugs tenofovir disoproxil fumarate (TDF) and tenofovir alafenamide (TAF) for repurposing against SARS-CoV-2, assessing key pharmacological indices (CC50, EC50, cytostatic effect, and therapeutic window). In vitro screening in Vero E6 cells measured cytotoxicity (via CCK-8/MTT assays) and antiviral activity against Kazakh B.1 and Wuhan strains. TDF (50 µg/mL) reduced high viral loads (MOI 2) by ~2 log10 (100% inhibition), with minimal cytotoxicity (≥75% viability). TAF achieved near-complete suppression (100% inhibition) at 50 µg/mL, exhibiting dose-dependent inhibition (68–100%) at lower viral loads (MOI 0.01). Both prodrugs showed enhanced antiviral activity with prolonged exposure (96 h). Synergy assessments demonstrated favourable combination indices (CI < 1). Electron microscopy confirmed virion integrity post-treatment. These findings highlight TDF and TAF as promising candidates against SARS-CoV-2, with particular potential for targeting lymphoid reservoirs—sites implicated in persistent viral reservoirs that may contribute to long COVID pathogenesis. Further clinical validation is warranted.