Not Medical Advice: Cheratussin AC is a prescription cough syrup, which is commonly used to treat chest congestion, coughing, pain, and other symptoms of many breathing illnesses. Qualitest is simply the name of the drug manufacturer, Qualitest Pharmaceuticals, based out of Huntsville, Alabama. It's generally prescribed as a temporary treatment for conditions such as bronchitis and sinusitis, rather than more chronic conditions such as emphysema or asthma.
Cheratussin AC is a medication made from the combination of the narcotic cough suppressant codeine and the expectorant guaifenesin. The main function of the codeine is to suppress coughing and relieve pain, while the guaifenesin loosens congestion in the chest and throat. This medication can have serious, sometimes fatal, side effects when not taken in the proper prescribed dosage, so it's highly recommended to follow the instructions given to you by your doctor and pharmacist.
Cheratussin AC is most often prescribed as a syrup, but also comes in tablet form. It can be taken with or without food, but it's suggested to take it with food if it upsets your stomach.
Though there have been no problems involving Cheratussin lately, there was a controversy involving Qualitest's oral contraceptives in September 2011. Due to a packaging error, multiple batches of oral contraceptives were recalled, but over 200 women became pregnant while using the faulty contraceptives. Despite this situation, sales have increased at Qualitest over the past 2 years and their parent company Endo has stated that they plan to increase Qualitest's manufacturing capacity in 2013.