Clinical Key's Drug Monographs provide users with descriptions of drugs that include such information as mechanism of action, pharmacokinetics, indications, dosage, interactions, and global drug names.
Database maintained by the U.S. National Library of Medicine that contains 100778 drug listings as submitted to the Food and Drug Administration (FDA).
Goodman and Gilman's the Pharmacological Basis of Therapeutics, 14th Edition by 
Basic and Clinical Pharmacology by 
