Coricidin, Coricidin 'D' (decongestant), or Coricidin HBP, is the name of an over-the-counter cough and cold combination drug containing dextromethorphan and chlorpheniramine maleate. Introduced by Schering-Plough in 1949 as one of the first antihistamines, it is now owned by Bayer. Varieties of Coricidin may also contain acetaminophen and guaifenesin.