Productive Cough with Allergy: When you have a cough accompanied by a runny nose, sneezing, or itchy eyes. Chronic Bronchitis: To thin thick mucus while calming airway irritation. Allergic Rhinitis: Managing seasonal allergies that lead to "post-nasal drip" (mucus dripping down the throat causing a cough). Asthmatic Bronchitis: Helping to clear airways clogged by sticky phlegm.