Effective Treatment of Chronic Cough with Tinidazole as the Newest Antiprotozoa against Lophomonas blattarum.

Background: Chronic cough is a common problem in the setting of family physicians. Recently, Lophomonas blattarum was considered a cause of respiratory symptoms in children and adults. Objective: This study is aimed at determining the effect of antiprotozoal treatment of Lophomonas in patients with a chronic cough in Mashhad during 2020-2021. Materials and Methods: This study was a randomized clinical trial. In this study, 60 patients with chronic cough and unremarkable imaging findings, who were unresponsive to three steps of standard treatment, were randomly assigned to the treatment, with 2 weeks of tinidazole and placebo. The tinidazole and placebo were prepared in a completely identical shape, and a random assignment was performed by a third party. The primary outcome was a complete resolution of cough. A follow-up of treatment was performed. Data were analyzed using the SPSS software version 25. Results: The basic demographic results showed no significant differences of sex and age between two groups. The results of this study showed a complete resolution of all respiratory symptoms in 40% (12), a complete improvement of cough in 40% (12), and a complete resolution of dyspnea in 50% (10) of the tinidazole group. The remaining showed significant improvement in the severity of cough and dyspnea. Postnasal drip, sputum, body temperature, and airway hyperresponsiveness were improved significantly. After tinidazole treatment, laboratory assessment of bronchial lavage and sputum revealed that 86 percent of smears were converted to negative. Conclusion: Tinidazole effectively resolved the chronic cough and most of the respiratory symptoms. Lophomonas blattarum is a potential mechanism for chronic cough.