There are many factors that go into choosing which local anesthetic is appropriate for a patient. Here are two links that may help you:
http://www.cypresscollege.edu/ad/uploads/400005/vasoconstrictors_part2.pdf
http://www.drmalamed.com/downloads/files/LA_ADA_PainPosterFront.pdf
If you still have your local anesthesia book from school, it may be good to go back and review. 🙂