As a prescribing g physician, these would be my comments (In the US):

1: It is not illegal to have meds on hand, IF PRESCRIBED (even controlled
Substances, though be prepared to explain to someone why you have a large quantity) keep in mind in Canada and much of Europe, codeine is available over the counter with a signature.

2: Most physicians will prescribe extended amounts of meds for patients they are familiar
with.

3: Most cost effective sources will be Costco and Wal-Mart (if drug is on the “$4 list”).

4: Build up a supply, then rotate out the oldest

5: Many drugs that don’t have a generic equivalent do have generic therapeutic substitutions (“same as, only different”)

6: References for First-aid supply needs:
Wilderness Medical Society: Practice Guidelines for Emergency Care, Fifth Ed.
William Forgery, M.D.

Wilderness Medicine, 5th Edition - Text with DVD by Paul S. Auer Bach, MD

7: General drug refences:
Epocrates –online
PDR – really just a collection of selected drug package inserts, good for trade
drugs, worthless for generics
Facts and Comparisons – probably best single source, groups drugs in classes,
gives off label uses, and compares prices (wholesale, not retail) – often available at the public library (many hospital and university libraries give public access with a simple request)
Sanford Guide to Antimicrobial Therapy- issued yearly, obviously antibiotics only