Tenofovir, Another Inexpensive, Well-Known and Widely Available Old Drug Repurposed for SARS-COV-2 Infection

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is spreading worldwide with different clinical manifestations. Age and comorbidities may explain severity in critical cases and people living with human immunodeficiency virus (HIV) might be at particularly high risk for severe progression. Nonetheless, current data, although sometimes contradictory, do not confirm higher morbidity, risk of more severe COVID-19 or higher mortality in HIV-infected people with complete access to antiretroviral therapy (ART). A possible protective role of ART has been hypothesized to explain these observations. Anti-viral drugs used to treat HIV infection have been repurposed for COVID-19 treatment; this is also based on previous studies on severe acute respiratory syndrome virus (SARS-CoV) and Middle East respiratory syndrome virus (MERS-CoV). Among them, lopinavir/ritonavir, an inhibitor of viral protease, was extensively used early in the pandemic but it was soon abandoned due to lack of effectiveness in clinical trials. However, remdesivir, a nucleotide analog that acts as reverse-transcriptase inhibitor, which was tested early during the pandemic because of its wide range of antiviral activity against several RNA viruses and its safety profile, is currently the only antiviral medication approved for COVID-19. Tenofovir, another nucleotide analog used extensively for HIV treatment and pre-exposure prophylaxis (PrEP), has also been hypothesized as effective in COVID-19. No data on tenofovir’s efficacy in coronavirus infections other than COVID-19 are currently available, although information relating to SARS-CoV-2 infection is starting to come out. Here, we review the currently available evidence on tenofovir’s efficacy against SARS-CoV-2.

HIV and SARS-CoV-2 Co-Infection: What are the Risks?

“…The protective role of tenofovir is a matter of debate, with conflicting evidence about its possible effect on COVID-19 prevention and treatment. 4 …”

“…The protective role of tenofovir is a matter of debate, with conflicting evidence about its possible effect on COVID-19 prevention and treatment. 4 Protease inhibitors, which had a role in treating the MERS-CoV infection, did not seem effective in preventing or treating SARS-CoV-2. 29 Once SARS-CoV-2 infection is acquired, risk of severe COVID-19 and hospitalization is higher in PLWH.…”

“… 3 PLWH could even experience protection from the most serious sequelae of COVID-19, because of their history of immune response or the hypothesized activity of Anti-Retroviral Treatment (ART) against SARS-CoV-2. 4 , 5 …”

“…3 PLWH could even experience protection from the most serious sequelae of COVID-19, because of their history of immune response or the hypothesized activity of Anti-Retroviral Treatment (ART) against SARS-CoV-2. 4,5 The interplay between SARS-CoV-2 and HIV is affected by several conflicting aspects. The residual chronic inflammation, present even in suppressed PLWH, and the immune deficiency due to HIV may exert opposite effects.…”

Correction: Zanella et al. Tenofovir, Another Inexpensive, Well Known and Widely Available Old Drug Repurposed for SARS-COV-2 Infection. Pharmaceuticals 2021, 14, 454

“…There was an error in the original article [ 1 ]. In the Abstract, page 1, line 12 from the top, the sentence “… remdesivir, a nucleotide analog that acts as reverse-transcriptase inhibitor, …” is incorrect.…”