Guaifenesin is an expectorant that works by thinning the mucus in the airways in the chest, making it easier to clear these passages, according to MedlinePlus. It does not treat the underlying cause of the cough or speed the patient’s healing.
People commonly use guaifenesin when suffering colds, allergies or infections. When using the medication, drinking plenty of fluids helps with the process of keeping the congestion loose and lubricating the throat to assist in clearing the airways, according to Drugs.com.
While patients generally tolerate guaifenesin with few to no undesirable side effects, it causes gastric disturbances and vomiting in users who take more than the label directions, reports Drugs.com. The medication can also cause headaches, dizziness and a skin rash. In people who exhibit a high sensitivity to guaifenesin, the medicine sometimes causes anaphylactic shock.
Guaifenesin is the active ingredient in cold medications such as Tussin, Mucinex and Vicks DayQuil, indicates MedlinePlus. It is also an ingredient in combination cough medications such as Zicam, Tussin DM and Mucus Relief DM.
When measuring liquid medication containing guaifenesin, the user should use the manufacturer’s cup or a measuring spoon to ensure the right dosage. When a cough does not improve within seven days or occurs with a headache, high fever or rash, it is important to contact a doctor, according to MedlinePlus.