For nursing school I need Davis Drug Guide for Nurses 11th ed. (2008), which costs around $30. The 10th editon (2006) of the book I found for around $1.50 on amazon
.com. Is it essential to have the newest up-to-date book on drugs or can I get by on the previous edition? I really want to save money, but at the same time I don't want anything that's too out of date. Thanks!