How do I despose of not needed meds?

My youngest daughter had her wisdom teeth removed and she was given Tylenol 3s and vicodin. She only needed one vicodin out of the 30 that I filled a prescription for and she has 13 Tylenol 3s left. She isn't in any pain anymore and been off the meds for a week. I had a friend tell me to keep them in case I needed them in the future. Well if I need them in the future a doctor will prescribe something for me and I'm sure the dosage would be different and it could be a different medication. I don't want to flush them down the toilet but I don't want them around taking up space. Where can I get rid of them safely?