Background Vitamin C is an essential water-soluble nutrient that functions as a key antioxidant and has been proven to be effective for boosting immunity. In this study, we aimed to assess the efficacy of adding high-dose intravenous vitamin C (HDIVC) to the regimens for patients with severe COVID-19 disease. Methods An open-label, randomized, and controlled trial was conducted on patients with severe COVID-19 infection. The case and control treatment groups each consisted of 30 patients. The control group received lopinavir/ritonavir and hydroxychloroquine and the case group received HDIVC (6 g daily) added to the same regimen. Results There were no statistically significant differences between two groups with respect to age and gender, laboratory results, and underlying diseases. The mean body temperature was significantly lower in the case group on the 3rd day of hospitalization (p = 0.001). Peripheral capillary oxygen saturations (SpO2) measured at the 3rd day of hospitalization was also higher in the case group receiving HDIVC (p = 0.014). The median length of hospitalization in the case group was significantly longer than the control group (8.5 days vs. 6.5 days) (p = 0.028). There was no significant difference in SpO2 levels at discharge time, the length of intensive care unit (ICU) stay, and mortality between the two groups. Conclusions We did not find significantly better outcomes in the group who were treated with HDIVC in addition to the main treatment regimen at discharge. Trial registration irct.ir (IRCT20200411047025N1), April 14, 2020

Introduction It is reported that coronavirus disease (COVID-19) can affect the sense of smell and taste of infected people. The pathobiology of this virus is still incompletely known, and it is therefore important to explore the impact of COVID-19 infections on olfactory and gustatory functions. We aimed to review current evidence on olfactory and gustatory dysfunctions caused by COVID-19. Methods This study was a narrative review performed in 2020 to investigate the olfactory and gustatory dysfunctions of the COVID-19. We searched eight keywords in six databases to determine the related documents on the main objective of the study. To discover studies meeting the inclusion criteria, the authors screened the titles and abstracts of the identified articles. The appropriate studies were included and their results were discussed to make the final selection. Results We have studied 24 current articles on the olfactory and gustatory dysfunctions due to COVID-19. A review of current studies has shown that we have a surge in the spread of olfactory and gustatory dysfunctions that happened during the epidemic of COVID-19 infection. Most studies (95.8%) have confirmed the symptoms of anosmia in patients with SARS-CoV-2 infection. A review of current studies showed that, in addition to anosmia, evidence of ageusia and dysgeusia (parageusia) was also seen in patients with COVID-19. Conclusion The results of our study support recent reports that SARS-CoV-2 may infect oral and nasal tissues and cause olfactory and gustatory dysfunctions. These findings may aid future research on the diagnosis, prevention, and treatment of COVID-19 consequences.

Highlights Ventricular arrhythmias can occur with concurrent use of azithromycin (AZM) and hydroxychloroquine (HCQ). Combination therapy with HCQ+AZM can reduce the hospital length of stay in COVID-19 patients. Preparatory risk assessment can limit the risk of arrhythmia in patients receiving HCQ+AZM combination therapy.