Clarithromycin in COVID-19 of moderate severity

The new SARS-CoV-2 Coronavirus (COVID-19) unpredictably aggravates pneumonia, causing some patients to deteriorate into severe respiratory failure due to a complex immune disorder. Because of its anti-inflammatory properties, Azithromycin has been included in the treatment algorithm since the beginning of the COVID-19 pandemic to reduce the hyperinflammatory response and prevent the development of severe respiratory failure. Furthermore, based on the findings of an open-label study that showed greater therapeutic efficacy when the two drugs were used together, Azithromycin was given in combination with hydroxychloroquine. Indeed, the anti-inflammatory properties of the macrolide antibiotic class have been mentioned in the American Thoracic Society guidelines since 2019, arguing in favor of combining -lactam antibiotics with macrolides to treat community-acquired pneumonia (CAP - Community-Acquired Pneumonia).

To assess Clarithromycin's therapeutic efficacy, Greek researchers conducted a non-randomized open-label trial in four medical institutions between May and October 2020, enrolling 90 patients with moderate COVID-19 and 90 patients in the control group. The 90 participants with respiratory tract infections were given 500 mg of Clarithromycin every 12 hours for seven days, while the control group received standard Azithromycin and Hydroxychloroquine treatment.

The main goal for upper respiratory tract infection was that the disease did not spread to the lower respiratory tract. For patients with lower respiratory tract infections, the respiratory symptoms score at the end of treatment should be reduced by at least 50%. The disease did not progress to severe respiratory failure. SARS-CoV-2 viral load, biomarkers, mononuclear cell function, and safety were assessed in Clarithromycin-treated patients; biomarkers were also measured in the control group.

The medical team conducted two randomized, double-blind, placebo-controlled clinical trials that found intravenous Clarithromycin associated with a significant reduction in the risk of death in patients with critical illness and Gram-negative sepsis. The first study was conducted in sepsis patients and revealed that 90-day survival was 40% in the placebo group and 57% in the Clarithromycin treatment group. In addition, mortality in community-acquired pneumonia, severe form, was 20.8 percent in patients treated with β-lactam and Clarithromycin and 33.8 percent in patients treated with β-lactam and Αzithromycin. Based on the evidence presented above, it appears that combining COVID-19 with Clarithromycin may reduce hyperinflammatory responses and the risk of severe respiratory failure progression.

In conclusion, the study's findings clearly show that Clarithromycin treatment in patients with moderate COVID-19 is associated with early clinical improvement and viral load isolation. This is linked to an increase in the Th1 / Th2 response rate. More research is needed in the future to define better the role of this antibiotic in mild to moderate COVID-19 forms.