This pilot, multicentric and observational study will assess the safety of sulfamethoxazole + trimethoprim + guaifenesin (Balsamic Bactrim) in pediatric participants with acute bronchitis. Administration of treatment will be according to treating physician's recommendation under local labeling.

Inclusion Criteria:

• Participants starting treatment with Bactrim Balsamic suspension
• Participants with a clinical diagnosis of acute bronchitis (cough with or without sputum production less than 30 days) according to the medical criteria

Exclusion Criteria:

• Participants who have started treatment with another antibiotic at the time of the visit
• Participants with no respiratory infections
• Participants with mental disorders that do not permit the clinical evaluation of the participant according to the treating physician's criteria
• Participants with severe hepatic parenchymal damage
• Participants with severe renal failure making it difficult to monitor drug plasma concentration
• Participants with hypersensitivity to any of Balsamic Bactrim active ingredients, excipients, and/or sulfas

Pediatric participants receiving treatment for acute bronchitis with Balsamic Bactrim according to standard of care and in line with the current summary of product characteristics (SPC) / local labeling and who have no contraindication to Balsamic Bactrim as per the local label.