How to use Guaifenesin DM Syrup. Take this medication by mouth with or without food, as directed by your doctor. If you are self-treating, follow all directions on the product package. Taking codeine and guaifenesin with other drugs that make you sleepy or slow your breathing can cause dangerous side effects or death. Ask your doctor before taking a sleeping pill, narcotic pain medicine, prescription cough medicine, a muscle relaxer, or medicine for anxiety , depression , or seizures. This syrup preparation combines the expectorant, guaifenesin, with the cough suppressant, codeine. Guaifenesin enhances the output of lower respiratory tract fluid. The enhanced flow of less viscid secretions promotes and facilitates the removal of mucus. Rugby® Cough Syrup Guaifenesin 100mg/5mL, 480 mL Per Bottle (4 Bottles) Taking codeine and guaifenesin with other drugs that make you sleepy or slow your breathing can cause dangerous side effects or death. Ask your doctor before taking a sleeping pill, narcotic pain medicine, prescription cough medicine, a muscle relaxer, or medicine for anxiety, depression, or seizures. Prices and coupons for 120 ml 6.25mg/10mg/5ml of promethazine / codeine syrup AFOAF used Guaifenesin containing cough syrup three times in a row when nothing was available. AFOAF did not feel any harmful effects from 4,000MG+ but he is very tolerant of stuff like this. AFOAF did not feel any harmful effects from 4,000MG+ but he is very tolerant of stuff like this. Find patient medical information for Codeine-Guaifenesin Oral on WebMD including its uses, side effects and safety, interactions, pictures, warnings and user ratings. Skip to main content Check. Lists the various brand names available for medicines containing guaifenesin. Find information on guaifenesin use, treatment, drug class and molecular formula. Guaifenesin 100mg/Codeine 10mg/5ml Syr - 118ml Unfortunately our full catalog may not be displayed in your state. If you contact our Customer Support by one of the methods below, we will be able to assist you in locating the product you are looking for.