Open Question: I received spam email that dug into my address book. How do I clean out my address book & stop the email?

I received an email from a distant acquaintance that asked me to be her friend (not on Facebook, some other entity). I then received another email from her saying not to open the first email Too late! I did open it before deleting it. It is supposedly spam that will replicate itself through my address book. Is there a way to clean my address book and prevent spreading this email to friends?