Acetaminophen and codeine combination oral solution or tablet can cause serious unwanted effects or fatal overdose if taken by children, pets, or adults who are not used to strong. Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical. Acetaminophen is used to relieve pain and reduce fever in patients. But acetaminophen may cause other unwanted effects. Acetaminophen and codeine phosphate tablets expose patients and other users to the risks of opioid addiction, abuse, and misuse, which can lead to overdose and death. Acetaminophen and codeine phosphate tablets are indicated for the relief of mild to moderately severe pain.