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Telmisartan and losartan: The marked differences between their chemical and pharmacological properties may explain the difference in therapeutic efficacy in hospitalized patients with COVID‐19

Year: 2023

Type: article

Abstract: At the beginning of the COVID-19 pandemic, Gurwitz, 1 taking into account that SARS-CoV-2 virus enters cells after binding to ACE2 (Angiotensin Converting Enzyme 2), proposed the hypothesis of the involvement of the RAS (Renin Angiotensin System) in the pathophysiology of this disease.Our adherence to the hypothesis led to the design of a clinical trial selecting telmisartan among the angiotensin AT1 receptor blockers (ARBs) at a dose of 80 mg twice a day, orally, for 14 days, for the treatment of hospitalized patients with COVID-19.2 On the contrary, also starting in April 2020, a clinical trial with losartan, another ARB, was designed in hospitalized patients with COVID-19, administering doses of 50 mg orally twice daily for 10 days (NCT04312009).Recently, Liu et al. 3 published the results obtained after analyzing 54 randomized controlled trials (RCTs) that compared 13 drugs for the treatment of patients with COVID-19 against placebo or standard care.Among the drugs selected for the analysis, they included two ARBs, telmisartan, and losartan.To evaluate the efficacy of the drugs included, covered all causes of mortality at 5-8, 14/15, 21-, 25-, 28/30, 35-, 45-, 60-, 70, and 90-days.Compared with the control group, only four drugs showed statistically significant efficacy in reducing mortality.Among these four drugs, the angiotensin II AT1 receptor blocker telmisartan stands out, which showed an 81% reduction in the risk of mortality at 30 days after oral administration in doses of 80 mg twice/day for 14 days and in hospitalized patients with COVID-19 not admitted to an intensive care unit and from no more than 4 days after the onset of symptoms.4 Conversely, losartan did not show oral efficacy at a dose of 50 mg twice daily for 10 days in hospitalized patients with COVID-19.5 On the contrary, a recent article 6 reported the results of an RCT of telmisartan treatment in COVID-19 patients.This study was conducted largely in India (99% of all subjects) during the period from May 3, 2020, to November 13 when the delta variant of SARS-CoV-2 was present.Telmisartan (40 mg daily) failed to reduce mortality.

Source: Pharmacology Research & Perspectives

DOI: 10.1002/prp2.1083