I have a bottle of Diabetic Tussin, is this safe to take after a year after it's expiration date? ## Hello, Pat! How are you? No, it has most likely gone bad by now. Liquid medications degrade much faster than other formulations and, if they sour, they may actually make you sick, if you take them once expired. The FDA classifies this as a cold remedy and its typical side effects may possibly include nausea, dizziness, dry mouth and headache. Is there anything else I can help with?