1. Lyu Y, Park SJ, Lee EJ, Jeon JH, Jung IC, Park YC. A systemic review of clinical trials using medication for acute bronchitis: a pre-study on the development of traditional Korean medicine clinical practice guideline. J Korean Med 2017;38:93–111.

2. Shubert N, Kühlein T, Burggraf L. The conceptualization of acute bronchitis in general practice - a fuzzy problem with consequences? A qualitative study in primary care. BMC Prim Care 2023;24:92.

3. Kinkade S, Long NA. Acute bronchitis. Am Fam Physician 2016;94:560–565.

4. Tackett KL, Atkins A. Evidence-based acute bronchitis therapy. J Pharm Pract 2012;25:586–590.

5. Matthys H, Eisebitt R, Seith B, Heger M. Efficacy and safety of an extract of Pelargonium sidoides (EPs 7630) in adults with acute bronchitis. A randomised, double-blind, placebo-controlled trial. Phytomedicine 2003;10:Suppl 4. 7–17.

6. Park MJ, Rhee CK, Kim YH, et al. Efficacy and safety of HL301 in the treatment of acute bronchitis and acute exacerbation of chronic bronchitis: a phase 2, randomized, double-blind, placebo-controlled, multicenter study. Curr Med Res Opin 2017;33:919–925.

7. Yoon SW, Park MJ, Rhee CK, et al. HL301 in the treatment of acute bronchitis: a phase 2b, randomized, double-blind, placebocontrolled, multicenter study. Korean J Intern Med 2020;35:133–141.

8. Kim WY, Park MJ, Rhee CK, et al. HL301 versus Umckamin in the treatment of acute bronchitis: a phase III, randomized, controlled, double-blind, multicenter study. Curr Med Res Opin 2020;36:503–508.

9. Dal Negro RW. Erdosteine: antitussive and anti-inflammatory effects. Lung 2008;186:Suppl 1. S70–S73.

10. Poole P, Sathananthan K, Fortescue R. Mucolytic agents versus placebo for chronic bronchitis or chronic obstructive pulmonary disease. Cochrane Database Syst Rev 2019;5:CD001287.

11. Ra SW, Kim SY, Lim YY, et al. The safety and efficacy of CKD-497 in patients with acute upper respiratory tract infection and bronchitis symptoms: a multicenter, double-blind, double-dummy, randomized, controlled, phase II clinical trial. J Thorac Dis 2021;13:1–9.

12. Yang WK, Lyu YR, Kim SH, Park YC. Effects of GHX02 on chronic obstructive pulmonary disease mouse model. J Korean Med 2018;39:126–135.

13. Lee SW, Lyu YR, Kim SY, et al. Efficacy and safety of GHX02 in the treatment of acute bronchitis and acute exacerbation of chronic bronchitis: a phase 2, randomized, double-blind, placebo-controlled, multicenter trial. Front Pharmacol 2022;12:761575.

14. Lee EG, Rhee CK. The clinical efficacy of AG NPP709 (Synatura ®) in patients with chronic bronchitis type stable chronic obstructive pulmonary disease. J Thorac Dis 2020;12:2435–2442.

15. Chang AB, Yerkovich ST, Baines KJ, et al. Erdosteine in children and adults with bronchiectasis (BETTER trial): study protocol for a multicentre, double-blind, randomised controlled trial. BMJ Open Respir Res 2024;11:e002216.

16. Marchioni CF, Polu JM, Taytard A, Hanard T, Noseda G, Mancini C. Evaluation of efficacy and safety of erdosteine in patients affected by chronic bronchitis during an infective exacerbation phase and receiving amoxycillin as basic treatment (ECOBES, European Chronic Obstructive Bronchitis Erdosteine Study). Int J Clin Pharmacol Ther 1995;33:612–618.

17. Agbabiaka TB, Guo R, Ernst E. Pelargonium sidoides for acute bronchitis: a systematic review and meta-analysis. Phytomedicine 2008;15:378–385.

18. Kardos P, Lehmacher W, Zimmermann A, et al. Effects of Pelargonium sidoides extract EPs 7630 on acute cough and quality of life - a meta-analysis of randomized, placebo-controlled trials. Multidiscip Respir Med 2022;17:868.

19. Lee JR, Min BG, Park CA, Kim SC, Park SJ. Anti-bacterial effect of fusion formulation of Coptis rhizoma and Pelargonium sidoides on the growth of bronchial diseases bacteria. Herb Formula Sci 2017;25:449–456. 20. Matthys H, Lizogub VG, Malek FA, Kieser M. Efficacy and tolerability of EPs 7630 tablets in patients with acute bronchitis: a randomised, double-blind, placebo-controlled dose-finding study with a herbal drug preparation from Pelargonium sidoides. Curr Med Res Opin 2010;26:1413–1422.

21. Timmer A, Günther J, Motschall E, Rücker G, Antes G, Kern WV. Pelargonium sidoides extract for treating acute respiratory tract infections. Cochrane Database Syst Rev 2013;2013:CD006323.

22. Brendler T, van Wyk BE. A historical, scientific and commercial perspective on the medicinal use of Pelargonium sidoides (Geraniaceae). J Ethnopharmacol 2008;119:420–433.

23. Kim SK, Chang J. Respiratory symptoms relievers: antitussives, mucolytics, antihistamines. Tuberc Respir Dis 2006;60:261–269.

24. Albrecht U, Stefenelli U, Stange R. A combination of Tropaeolum majus herb and Armoracia rusticana root for the treatment of acute bronchitis. Phytomedicine 2023;116:154838.