Pulmonary fibrosis is a devastating disease that leads to progressive scarring of the lungs. Fibrotic scarring causes lung tissue stiffness, which leads to breathing difficulties and reduces oxygen concentration in the bloodstream, ultimately resulting in organ failure. For treating pulmonary fibrosis, presently the pharmacological arsenal involves only two drugs, pirfenidone and nintedanib, which work to slow down the disease progression but do not completely halt its advancement. In other words, there is no permanent cure for it. This is why the latest research findings on an over-the-counter cough syrup ingredient (dextromethorphan) having the potential to treat pulmonary fibrosis have given a new ray of hope to those afflicted by pulmonary fibrosis.
The research, which was published in the December 2024 edition of the Science Translational journal and conducted by the scientists at the European Molecular Biology Laboratory (EMBL), has shown how dextromethorphan, which is available as a cough medicine around the world, can impede the collagen that forms scars inside cells, reducing lung fibrosis. Dextromethorphan, a common ingredient present in cough syrups due to its antitussive properties, has been studied in various experimental models, including the scar-in-a-jar model, human precision-cut lung slice models, and lung fibroblasts (cells involved in lung scarring).
According to Dr. Sanjith Saseedharan, Director- Critical Care, S L Raheja Hospital- A Fortis Associate, “What makes this research particularly exciting is the discovery that dextromethorphan works through a different mechanism of action than previously understood. This opens up the possibility of combining it with drugs like nintedanib or pirfenidone, potentially enhancing its therapeutic effects. So far, individuals diagnosed with pulmonary fibrosis in the 50-60 age group have an average life expectancy of about five years, with this expectancy being even shorter for those over 60. Thus, if the findings of this research are cleared after a successful and rigorous human trial, it will usher in a new era of hope for those whose lives have been marred by pulmonary fibrosis.”
According to Dr. Swapnil M. Khadake, Chief Intensivist at Fortis Hiranandani Hospital Vashi, “Dextromethorphan has been widely used for many years, and physicians are already familiar with its effects and side effects. This makes it a classic example of repurposing a US Food and Drug Administration-approved drug, which could be brought to market much faster compared to developing an entirely new molecule. Also, it is important to note that almost 20–30 percent of patients undergoing treatment for pulmonary fibrosis discontinue drugs like nintedanib or pirfenidone due to gastrointestinal issues, photosensitivity, and cost. The recent research in this regard thus becomes a very important progress in the treatment of a disease in which medicine has so little to offer those suffering from it.”
However, while these findings are promising and thought-provoking, further translational research in animal models and, eventually, human trials is necessary to validate the molecule’s effectiveness beyond the experimental models.
The scientists originally associated with the project plan to further investigate the drug, why it works, and how it works. This will hopefully identify how the drug works in cells in the disease context, offering the possibility of developing improved variants of it. Nonetheless, this development offers hope and could represent a significant breakthrough for a disease that affects 13 to 20 out of every 10,000 people worldwide, as well as for the medical community dealing with lung fibrosis. It has the potential to be a “light at the end of a dark tunnel.