Some of the side effects of using acetaminophen with codeine are shallow breathing, seizures, easy bruising or bleeding, and fainting, according to RxList. Users should contact a doctor immediately if they experience any of these serious side effects when using this medication.
This medication may also cause an allergic reaction, as RxList reports. Some of the sings of an allergic reaction are the presence of hives, difficulty breathing, and swelling of the face, lips, tongue or throat.
Acetaminophen with codeine usually comes in the form of a 300 mg tablet of acetaminophen that also includes either 30 or 60 mg of codeine. Acetaminophen is the active ingredient in Tylenol, and the medication is also sometimes referred to as Tylenol with codeine. While acetaminophen is not habit forming, the codeine phosphate that is included in with it may be.
Less serious side effects of Tylenol with codeine include feeling dizzy or drowsy, mild nausea and vomiting, headache, blurred vision, and dry mouth, as RxList explains. When taking this medication, it is important not to take more than the prescribed amount because doing so can damage the liver and possibly cause death. Drinking alcohol when using Tylenol with codeine also increases the risk of liver damage, and the medication may also impair the user's thinking, judgment and reactions. Users are advised not to drive or operate machinery until they understand how the medication affects them individually.