Mentor for PI left institution. Study was not renewed.

This study is a randomized prospective study to compare the post-operative analgesic efficacy of intravenous acetaminophen 15 mg/kg to an equal volume of 0.9% normal saline when all other analgesic interventions have been standardized for all patients enrolled.

Inclusion Criteria:

1. The subject is age 3 to 10 years (inclusive)
2. The subject weighs more than 10.0 kg (inclusive of the tenth kilogram)
3. The subject is scheduled for the following: Elective tonsillectomy or tonsillectomy with adenoidectomy scheduled on an outpatient basis, with acceptable inclusion of patients also having PETs and/or EUA of ear
4. The subject is ASA patient classification I-II
5. The subject's legally authorized representative has given written informed consent to participate in the study and when appropriate, the subject has given assent or consent to participate.

Exclusion Criteria:

1. Additional surgical procedures are being performed concurrently;
2. The subject is ASA classification > II;
3. The subject has pre-existing allergy or known hypersensitivity to acetaminophen;
4. The subject receives midazolam as a premedication;
5. The subject has a history of chronic malnutrition;
6. The subject has any other condition, which in the opinion of the principal investigator, would not be suitable for participation in the study

Clinical research coordinator, parent and participant will be masked until participant is discharged from hospital. OR staff will not be masked.