If you misspell the word, the dictionary server may offer a list of close matches as alternatives. You absolutely can't do without this site. If there's a new drug and it's not in your new PDR, you need to look here. From there, it's just like doing a search at your local library. Medicine.net Medications Index Alphabetical listing of drugs.
Brand names are in all caps, generic names are in all lowercase for easy identification.
Each name is also linked to a prescription information page laid out much like a PDR, with links to more information about related diseases, conditions, et cetera, if you need to find out more. Other helpful links on their site as well. The Merck Manual of Diagnosis and Therapy Search for a word, phrase, or look through the table of contents. A wonderful search tool if you don't know what you're searching for. If you're not sure of the spelling, type in the first few letters.