I need a site that shows over the counter drug substitutes for prescription drugs

22as - thanks for your very interesting question.

Here is a resource that should help you with what you are seeking:

http://www.ncpa.org/pub/st/st262/st262f.html

This is from the NCPA, the National Center for Policy Analysis.

I was unable to find a site of the type you are looking for, perhaps
another researcher will be able to!

thanks,
ragingacademic

On this page you'll find a table entitled "Prescription Drugs Now
Available as Over-the-Counter Products" that you may find useful.
Choose a category (Analgesics, Histamine Antagonists, Antifungal
Medications, Smoking Deterrents, Mast Cell Stabilizer, and Topical
Medications), click on the category name, and you'll get a list of
over-the-counter drugs in the category that were once available only
by prescription.

http://www.aafp.org/afp/980501ap/jacobs.html