It really depends on where you live. The best thing to do is to call your local Public Health Dept. This number can be found in the phone book or online for the city you live in. Some cities have drug drop offs, often within the police dept or public health themselves. Otherwise you will need to ask them what disposal method they recommend. I know in my state that Pharmacies can no longer perform this service, not sure if it is the same everywhere.
Check if your local pharmacy has an unused medication disposal program if it does not wrap and throw them in the garbage. However you should not flush them in the toilet as they may contaminate the water.