guaifenesin and dextromethorphan hydrobromide (Robitussin and Mucinex Formulas)

  • Pharmacy Author:
    Omudhome Ogbru, PharmD

    Dr. Ogbru received his Doctorate in Pharmacy from the University of the Pacific School of Pharmacy in 1995. He completed a Pharmacy Practice Residency at the University of Arizona/University Medical Center in 1996. He was a Professor of Pharmacy Practice and a Regional Clerkship Coordinator for the University of the Pacific School of Pharmacy from 1996-99.

  • Medical and Pharmacy Editor: Charles Patrick Davis, MD, PhD
    Charles Patrick Davis, MD, PhD

    Charles Patrick Davis, MD, PhD

    Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

What is the dosage for Mucinex DM?

Adults and children 12 years of age and older:

  • Robitussin DM and Robitussin DM Maximum Strength (liquid): Take 10 ml by mouth every 4 hours as needed. No more than 6 doses in 24 hours.
  • Mucinex Fast-Max DM: Take 20 ml by mouth every 4 hours. No more than 6 doses in 24 hours.
  • Robitussin DM Maximum Strength (capsules): Take 2 capsules by mouth every 4 hours as needed. No More than 12 capsules in 24 hours.
  • Mucinex DM: Take 1 or 2 tablets by mouth every 12 hours. No more than 4 tablets in 24 hours.
  • Mucinex DM Maximum Strength: Take 1 tablet by mouth every 12 hours. No more than 2 tablets in 24 hours.

Safe and effective use of guaifenesin and dextromethorphan is not established for children under 12 years of age.

Which drugs or supplements interact with Mucinex DM?

Guaifenesin/dextromethorphan should not be used with MAO inhibitors like phenelzine (Nardil), selegiline (Zelapar, Emsam, and Eldepryl), tranylcypromine (Parnate), procarbazine (Matulane), rasagiline (Azilect) and isocarboxazid (Marplan). Such combinations increase the risk of serious side effects. Guaifenesin/dextromethorphan should not be used within 14 days of using a MAO inhibitor.

Medically Reviewed by a Doctor on 11/1/2016

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