Mucoactive Agents in the Therapy of Upper Respiratory Airways Infections: Fair to Describe Them Just as Mucoactive?

BACKGROUND: Upper and lower respiratory tract infections are common conditions for which medical advice is sought, and their management relies on the use of prescription and over-the-counter (OTC) medicines. Ambroxol, bromhexine, carbocysteine, erdosteine, N-acetyl cysteine (NAC), and sobrerol are mucoactive agents for which clinical trials have been conducted, have been awarded well-established status by regulatory authorities, and are available as OTC or prescription products. OBJECTIVE: To briefly review the evidence-based efficacy and safety of these substances in the therapy of upper respiratory airways infections. METHODS: We conducted searches in MEDLINE and other databases for clinical trials and reviews done on the efficacy and safety of ambroxol, bromhexine, carbocysteine, erdosteine, NAC, and sobrerol. RESULTS: Clinical trials have shown that these mucolytics have an important place in the relief of cough symptoms by easing the elimination of mucus. All drugs have shown comparable efficacy in the symptomatic treatment of productive cough, with some shared characteristics and some specific features. CONCLUSIONS AND RELEVANCE: All mucolytics reviewed have a good safety profile, although some precautions should be taken when using ambroxol and bromhexine, and the use of NAC and carbocysteine should be monitored in special patient groups. Overall, however, the available evidence from randomised, controlled, and observational trials, as well as pragmatic, real-life experience, suggests that these products are useful in the therapy of upper respiratory airways infections, including bronchitis, sinusitis, and rhinosinusitis.