Is it safe to take 3-year expired Guaiatussin that has been refrigerated? ## It is not advisable, since liquid medication can go rancid, once expired, even if refrigerated, and taking them could actually make you sick. If you need this medication, it would be best to obtain a fresh supply. The FDA lists the typical side effects of Guaiatussin AC as possibly including nausea, dizziness, headache, and dry mouth. Ref: Guaiatussin AC information What symptoms are you experiencing? ## Horrible coughing phlegm can’t breathe minor asthma flair up sick a dog. Don’t know about the Zoc Doc to call in a new RX