Can i take mucinex (guaifenesin) dm and claritin d?

Yes: These medications can be taken together because each has a different mode of action. Mucinex (guaifenesin) is prescribed to loosen the mucus. Claritin-d is an antihistamine and a decongestant. So the two of the drugs together should 1.) loosen the secretions, 2.) Claritin should decrease any allergic reaction and the decongestant should decrease mucus production.