Treating viral cough: a role for guaifenesin

There are multiple viruses responsible for upper respiratory tract infections (URTIs), consequently, there is no cure, but current treatments can provide symptomatic relief. The cough is a common and bothersome symptom of the URTI. This review article discusses clinical evidence and mechanisms of action of the ingredients used regularly in over the counter (OTC) cough and cold preparations to help relieve cough associated with the URTI. The roles of expectorants and mucolytics in cough are explored as well as the cough suppressants codeine and dextromethorphan. Furthermore, the importance of demulcents is discussed showing that this excipient acts rapidly to relieve cough, allowing time for the active ingredients to work. Finally, the role of the expectorant guaifenesin in alleviating cough is considered. Over the last few decades, our understanding of the mechanisms of cough have greatly advanced. With this knowledge, we can further develop our understanding of mechanisms of action of these ingredients and improve OTC cough and cold preparations to provide better relief for patients.