Which medication is classified as an expectorant?

Robitussin is recognized as an expectorant because it contains guaifenesin, a drug specifically designed to help loosen mucus in the airways and improve respiratory function. By decreasing the viscosity of mucus, it facilitates easier coughing and promotes clearing of the airways, making it effective in treating conditions where mucus buildup is a problem, such as colds and bronchitis.

In contrast, other medications listed serve different purposes. Maalox is an antacid that addresses symptoms of heartburn and indigestion. Ambroxol is also an expectorant, but its classification as a medication can vary depending on the specific formulation and regional usage, making Robitussin a more universally recognized expectorant in this context. Miralax is an osmotic laxative used to treat constipation and does not affect mucus production or clearance in the respiratory tract. Thus, Robitussin stands out as the clear choice in this scenario, owing to its well-established role in aiding expectoration.