Compare prices and print coupons for Cheratussin AC and other drugs at CVS, Walgreens, and other pharmacies. Prices start at $15.30. Guaifenesin is an expectorant that helps thin and loosen mucus in the lungs, making it easier to cough up the mucus. Codeine is an opioid cough suppressant (antitussive) that affects a certain part of the brain, reducing the urge to cough. Codeine/guaifenesin is a cough syrup that contains an expectorant and an opioid. It's used to help loosen mucus and calm coughs in adults and older children. Codeine/guaifenesin is taken by mouth, typically every 4 hours as needed. Guaifenesin and codeine phosphate is a drug prescribed for the treatment of cough caused by conditions such as the flu, cold, bronchitis, or sinusitis. Taking this medication with alcohol or other drugs that can cause drowsiness or breathing problems may cause very serious side effects, including death. Also, other medications can affect the removal of this product from your body, which may affect how it works. Cheratussin DAC is a combination medicine used to treat cough, stuffy nose, and sinus congestion caused by allergies, the common cold, or the flu. Cheratussin DAC will not treat a cough that is caused by smoking, asthma, or emphysema. Overview: Codeine/guaifenesin is a combination medicine used to reduce coughing and loosen mucus from the common cold or allergies. It works by affecting the part of the brain that controls the. Cheratussin AC is a combination medicine used to treat cough and chest congestion caused by allergies, the common cold, or the flu. Cheratussin AC will not treat a cough that is caused by smoking, asthma, or emphysema. Stop use and ask a doctor if cough lasts more than 7 days, comes back or is accompanied by fever, rash, or persistent headache. These could be signs of a serious condition. If pregnant or breast-feeding, ask a health professional before use. Keep out of reach of children. Cheratussin AC is a medication commonly prescribed by healthcare professionals to relieve coughs caused by colds, flu, or other respiratory infections. It contains two active ingredients: codeine, which is a narcotic cough suppressant, and guaifenesin, which is an expectorant.