Not Medical Advice: While we found no online information about the interactions between Robitussin (dextromethorphan /guaifenesin) and Zyrtec (cetirizine), this does not necessarily mean that there are no interactions exist. Sources suggest that you should consult your doctor or pharmacist.
Dextromethorphan / guaifenesin is in the drug class “upper respiratory combinations”, temporarily relieving cough due to the common cold, hay fever, upper respiratory tract infections, sinus inflammation, sore throat, or bronchitis.
Zyrtec is a member of the drug class “antihistamines”, used to treat cold or allergy symptoms such as sneezing, itching, watery eyes, or runny nose.
What we found is a moderate drug interaction of Robitussin-AC (codeine/guaifenesin) and Zyrtec (cetirizine) from Drugs.com, however using cetirizine together with codeine may increase side effects such as dizziness, drowsiness, and difficulty concentrating.
Having a cough can be uncomfortable and annoying when you are trying to get through your day, and a cough that acts up at night can also disrupt your sleep. Check out some tips that can help tame the hacking at Everydayhealth.com.