My son who's 10 just had a tonsillectomy on Tuesday(12/23/08). He started complaining about a headache and pain in the back of his neck last night. He is taking Acetaminophen-Codeine Eliximor for pain and amoxicillin to prevent infection. My husband and I can not take anything with Codeine because We always get a painful headache. Could this be the problem causing the headache and neck pain? Other than the headache and neck pain, he is doing quite well. He's able to eat and drink without pain. He runs a slight fever ever now and then, but that goes away with he takes his medicine. He is sleeping through the night. He doesn't have a lot of energy but that's understandable after surgery. Should I be concerned with the headache and neck pain? If he continues to complain should I call his doctor for a different pain medicine?