What Is The Expiry Date For Oxycodone Pills?

Thanks. I cannot find my oxycodone bottle and I just filled it last week. I happen to have a bottle of 11/07/11 pills from an old elbow fracture & surgery; may I use them? How long do these pills "last?" (I have MS pain; I'm a 60-yr old woman in otherwise great shape and health - exercise daily, etc.)