Paracetamol is a common medicine for pain and for bringing a fever down. It does not contain aspirin, so people who cannot take aspirin are often given this instead. In the United States the same drug is usually called acetaminophen; the tablet is the same idea with a different name. You buy it at a pharmacy for a headache, a cold, or a child’s fever. Used as the packet says, it is ordinary and widespread; taking too much is dangerous for the liver, which is why adults are told not to stack extra doses or mix several cold medicines that all hide the same drug inside. Though actually, in a Taiwanese home the box on the shelf is very often a brand name, and that is the word people ask for at the pharmacy.