Micromedex Search across multiple resources at once. It has more extensive referencing than other major drug databases, with some info on investigational and non-US drugs as does Martindale (a European drug database) which is included in the Micromedex package. It also contains a drug identification tool ("Identidex"), a drug interaction checker, specialized tools for IV drugs, drug reactions and dosage calculations, patient handouts, summary drug documents and three teratology databases.