Tussin DM is a widely available, over-the-counter medication for the treatment of coughs that may result from allergies or a respiratory infection. This type of medication works to both suppress the urge to cough and to loosen any phlegm that has accumulated in the lungs. Although different formulations may have slightly different ingredients, the active ingredients in all forms of Tussin DM are, typically, the same.
Dextromethorphan Bromide
As Drugs.com explains, one of the main active ingredients in Tussin DM is dextromethorphan bromide. Dextromethorphan bromide is a chemical that acts as a cough suppressant (also known as an anti-tussive). This drug works by blocking the chemical signals in the brain that lead to the cough reflex. Because dextromethorphan affects the nervous system, it can cause impaired alertness and drowsiness, so it should not be used by people who are using heavy machinery or are performing a task that requires alertness. Drinking alcohol while taking Tussin DM can increase these side effects. Patients should also avoid consuming caffeine or other stimulants while using Tussin DM, as the combination can produce agitation and restlessness, as well as nausea.
Guaifenesin
Guaifenesin is another active ingredient found in Tussin DM. Guaifenesin is an expectorant, which means that it works to loosen the phlegm and mucus in the lungs. RxMed says that guaifenesin increases the amount of fluid that the cells in the lower part of the respiratory tract produce. This makes any mucus that has accumulated in the lungs less viscous, which makes it easier to cough up. This helps ensure that any coughing that does occur while a patient is taking Tussin DM removes mucus from the lungs, which helps relieve the urge to cough in the future.
Inactive Ingredients
There are a variety of inactive ingredients in Tussin DM. These components do not have any medicinal effect on the body and are, instead, used to alter the medication's taste, color and viscosity. They may also function as preservatives. The exact inactive ingredients may vary from one manufacturer to the next. Drugstore.com lists the inactive ingredients in the Rite Aid brand of Tussin DM as purified water, saccharin sodium, citric acid, flavorings, FD&C Red 40 (a food-coloring dye), glycerin and sodium benzoate.
