You can’t take multiple cold medicines together, because most cold medicines are compound preparations, which means that there may be multiple ingredients, and if you take cold medicines together, it may cause adverse reactions to be superimposed, resulting in overdose and repeated use of medicines. Not only can you not take multiple western cold medicines together, but you also can’t take Chinese herbal medicines as well as western cold medicines together because many proprietary Chinese cold medicines also contain western acetaminophen or chlorpheniramine, etc., which may also increase the risk of adverse reactions, such as excessive sweating, dizziness, drowsiness, palpitations, tightness in the chest, shortness of breath, and allergies, etc. If you combine them together, you will be at a higher risk for adverse reactions.