Mucinex works by making the mucus thinner and less sticky thus making it easy for a person to cough. The drug is used to treat the symptoms of cough caused by flu and common colds.
People who are allergic to guaifenesin or other ingredients of Mucinex are advised not use the drug. Pregnant women, people with chronic cough and those using other medicines should talk to a health care provider prior to using Mucinex. Mucinex can be taken with extra fluids and with or without food as directed by a doctor. Common side effects of this medicine includes nausea and vomiting, as stated by Drugs.