Bromhexine Hydrochloride: Potential Approach to Prevent or Treat Early Stage COVID-19 D. Stepanova, P. Lierza aDepartment of Anesthesiology, Intensive Care, Pain Management and Palliative Care, Marienkrankenhaus, Soest, Germany Address Correspondence to Dmitry Stepanov,
[email protected], Tel. 0049-2921-3917673 Abstract The most critical step during viral infection is when viruses enter the cell. A novel coronavirus SARS-CoV-2 penetrates into alveolar cells through the transmembrane serine protease TMPRSS2. Extensive studies show that a clinically approved drug from Japan and South Korea, camostat mesylate inactivates TMPRSS2 in order to prevent the infection. However, these basic studies have not been translated to “bedside”, and their effectiveness has not been clinically confirmed yet. Here, we describe another potential antiviral substance, commonly used in the clinical practice as a mucolytics – bromhexine hydrochloride. Causing only few mild side effects, it may serve as either a new therapeutic strategy during early stages of the disease or a preventive agent blocking SARS-CoV-2 entry into alveolar cells through TMPRSS2. Therefore, in this review, we discuss these possible approaches based on the current data. Keywords SARS-CoV-2; COVID-19; TMPRSS2; bromhexine; prophylaxis; therapy Introduction An emerging international outbreak of the novel coronavirus SARS-CoV-2 has already become a problem for physicians and scientists globally. Although the majority of patients withstand the novel 2019 coronavirus disease (COVID-19) without vital threats, many people develop severe respiratory failure, leading to fatal consequences. A clinical trial from Wuhan, China has demonstrated, that 86% of the patients who required invasive ventilation and 79% among those who needed a non-invasive ventilatory support died in intensive care units (ICU) [1].