Effect of Andrographis paniculata treatment for patients with early-stage COVID-19 on the prevention of pneumonia: A retrospective cohort study

There is a need for safe and cost-effective treatments for COVID-19. Andrographis paniculata (AP) is an herbal plant that has been used for centuries to treat upper respiratory tract infections. Andrographolide is the major active component of AP that inhibits intracellular SARS-CoV-2 replication and has anti-inflammatory action. We performed a retrospective cohort study to evaluate the therapeutic and adverse effects of oral AP-products on COVID-19 by using the risk of pneumonia diagnosed by chest radiography as an indicator. This study included patients 15 to 60 years of age with laboratory-confirmed early-stage (asymptomatic or mild) COVID-19 without comorbidities at seven hospitals in three adjacent provinces in Thailand, between December 2020 and March 2021. Patients were treated for five days with either AP-extract (60 mg andrographolide, 3 times daily) or crude-AP (48 mg andrographolide, 3 times daily), when available. Patient information was prospectively recorded in the structured medical records and retrospectively reviewed. All eligible patients who received AP-treatment were included and control patients who did not receive AP-treatment were randomly selected using a ratio of approximately 1:1. Pneumonia occurred in 1/243 AP-treatment patients and 69/285 control patients. The risks of pneumonia after adjusting for confounding effects were 0.3% (95%CI, 0%-0.9%) and 24.3% (95%CI, 19.0%-29.7%) in the AP-treatment and control groups, respectively. The number needed to treat to avoid pneumonia development in one patient was four (95% CI, 3-5). Eight patients developed mild adverse events. AP-treatment regimens are acceptably safe and associated with highly reduced rates of pneumonia for patients with early-stage COVID-19.