Key takeaways
Mucinex D (guaifenesin/pseudoephedrine) and Deconex DMX (dextromethorphan/guaifenesin/phenylephrine) are both over-the-counter medications used for relieving symptoms of congestion and cough, but they have different ingredients and uses. Mucinex D combines an expectorant (guaifenesin) with a decongestant (pseudoephedrine) to help loosen mucus and relieve nasal congestion and sinus pressure. It only comes as an extended-release tablet that is taken every 12 hours. Deconex DMX is available in tablet or liquid formulations and includes a cough suppressant (dextromethorphan), an expectorant (guaifenesin), and a decongestant (phenylephrine). It addresses cough, nasal congestion, and sinus pressure, and is taken every 4 to 6 hours. Both of these medications may not be suitable for people with certain health conditions like heart disease or diabetes. Common side effects of Mucinex D is trouble sleeping and headache, while Deconex DMX can cause dizziness and sleepiness.
