Mucinex DM is used to treat coughs and cold symptoms. It contains two different medications; guaifenesin, which is an expectorant that loosens and expels mucus, and dextromethorphan HBr, which suppresses coughs, notes WebMD. Adults and children over the age of 12 years can use Mucinex DM, but children under the age of 12 should not use this medication, states the Mucinex website.
Mucinex DM comes as an extended release bi-layer tablet, which contains the active ingredients of 600 milligrams of guaifenesin and 30 milligrams of dextromethorphan HBr, states the Drugs website. Some inactive ingredients are cellulose, magnesium stearate and sodium starch glycolate.
The recommended dosage for this medication, which is taken with water, is one to two tablets every 12 hours, but the total dosage should not exceed four tablets in a 24-hour period. It is important not to chew or break up the tablet.
Although Mucinex DM may not cause any serious reactions in most people, there are some side effects associated with this medication, such as dizziness and possible allergic reactions, notes WebMD. Mucinex DM may interact with other medications, such as monoamine oxidase inhibitors, which could have fatal consequences. In case of an overdose, seek medical attention, especially if there are symptoms such as seizures and breathing difficulties.