LAUSR

1. The aim of their study was to compare, using a randomised clinical trial in hospitalised patients with COVID19 and primary hypertension, the effects of losartan and amlodipine using two primary outcomes: 30day mortality and length of hospital stay. In the design of such study, the calculation of the number of subjects required is mandatory, and it has not been reported in the methods section. Taking into account the mortality rate of COVID19 in inpatients in Iran with hypertension (10%14%1,2 mean 12%), the expected difference, if one of the drugs was associated with lower mortality, could be 50%. With an alpha coefficient of 5%, a beta power of 90%, an expected difference of 50% (6% versus 12%) and a bilateral test (no a priory hypothesis of superiority of amlodipine or losartan), the number of subjects in each group must be of at least 465 (163 for an expected difference of 75%, 3% versus 12%). The same comment can be done for the second primary outcome. Hence, the study should be considered as underpowered to answer the research question. 2. One risk factor of mortality in COVID19 patients is the age,2 and in this study, a stratified randomisation of age has not been done, the mean age of the groups was 67.3 years and 60.1 years, respectively. 3. The authors reported the results of a recent retrospective3 study that found significant improvement in mortality in COVID19 patients with hypertension receiving either nifedipine or amlodipine comparatively with patients receiving other or no hypertensive treatment. Moreover, two other retrospective studies4,5 found significantly reduced mortality in COVID19 patients treated by amlodipine than patients treated by other medications. Contrary to the study by Masoud NouriVaskeh et al, the three cited studies were performed in patients who were chronically treated by amlodipine. This point is important as studies5 have suggested that a chronic administration of amlodipine allowing to reach the steady state (ie at least 9 to 18 days given the elimination halflife of amlodipine: 30 to 60 hours6) could be necessary to achieve the inhibition of acid sphingomyelinase explaining the protective effect in COVID19 infection. Moreover, the fact that losartan and its carboxylic active metabolite have much shorter elimination halflives (about 2 hours and 69 hours, respectively) compared with amlodipine may constitute a bias that may favour losartan for which steady state is achieved more rapidly.