encyclopedia of medical concepts

How to use this site

Most pages have two sections. On the left of the page is the medical concept explorer, like the one on the left of this page. On the right is the page content, which in the case of the front page is the large search form.

Concept Explorer

You can click on the plus sign in a box () to expand the concept tree down one level.  You can also click on the name of the concept in order to display the page associated with that concept.


The search box on the front page and the top search box on the left of the page do the same thing. If you type in a word or part of a word in the search box, it will search for concepts and drugs that begin with the letters you typed. The search will bring back hyperlinked results in two columns, with concepts on the left and drugs on the right. 

For instance, search for the term "propantheline".  The search may be slow the first time.  Click on the first concept, "Propantheline".  You will get a page describing this class of substances, explaining that this is a muscarinic antagonist.  In the right column is a list of drugs made with that substance or related substances.  Click on the second one, Propantheline Bromide.  The window goes gray and a box comes down showing information about that drug, including the manufacturers, the doses, therapeutic equivalents and generics, and recently reported reported suspected adverse drug reactions.  On major drugs, there is also the FDA's documents linked to that page, including the approved label, product reviews, and correspondence between the FDA and the pharmaceutical firm.  Click on "Close" or anywhere on the grayed page to exit.

The second search box that sometimes appears at the bottom on the left is Google search. This uses the Google search engine, and can search the Reference.MD site only. Google search finds the search term anywhere in the text, not just at the beginning of the title.

Concept Page

There is all sorts of useful information on the concept page. The little tree symbol (ψ) is a link to the concept explorer on the left of the page. In some cases there is more than one such symbol. That means that this concept appears in several different places in the concept hierarchy. You can click on the different symbols to see the alternate ways of finding it in the concept hierarchy. Hovering over the link gives the name of the parent concept, for concepts that have several possible parents.

Underneath the title is the description of the concept. This description was defined to guide those who catalog articles, so as well as the description of the concept it describes how it relates to other concepts on this site. When words are in capitals and hypertexted, you can launch a search by cliking on them. For any other word in the text, double-clicking on the word launches a search for that word.

If the concept is within "Chemical and Drugs", the concept page may also show pharmacological actions, other names for the concept or chemical, and in the rightmost column, commercial drugs that have it or something related as an ingredient. There may also be a table of related substances classified under that concept, each with its CAS (Chemical Abstracts) registry number and names, each with a set of descriptors for their classification, each potentially with distinct pharmacological actions, and each listing citation references and commercial drugs, if any.

PubMed Lookup

On most concept page you will see a link "PubMed" in the upper right hand corner. That will look up recent articles in the medical literature (on the PubMed system, a service of the National Center for Biotechnology Information) where that term is a major topic of the paper. For most substances, there is one or more citation references in which the indexing concept was first found. Clicking on one of these also looks up that reference on PubMed. Please note that while PubMed is very comprehensive, it does not necessarily contain all of the references cited, either because the journal name is not recognized, or not indexed, or because the reference has a typographical error. Feel free to edit the search query to be more general if the search for the reference does not find it.

Drug Page

The drug page, which shows up when a drug name is clicked in the rightmost column, contains information about the drug, provided by the U.S. Food and Drug Administration. Please refer to the FDA's "Drug Nomenclature Monographs" for exact definitions of the information in these tables. In the first table is the list of different forms, dosages, and therapeutic equivalence codes of the drugs, allowing comparion between different brands of drugs. For each of them there may be documents available. If the document is hyperlinked, it can be seen on the FDA web site. Please note, many of the documents are in PDF format, which requires that your have the Adobe Acrobat Reader to view it. The second table summarizes reported drug adverse effects within one quarter. Adverse drug reaction reports are received from manufacturers, health care professionals and consumers. For any given report, there is no certainty that a suspected drug caused the reaction. This is because physicians are encouraged to report suspected reactions; however, the event may have been related to the underlying disease being treated, or caused by some other drug being taken concurrently, or simply occurred by chance at that time. This table cannot be used to calculate incidence (occurrence rates) or to estimate drug risk. Comparisons between drugs cannot be made from these data.

This site is now in production, and being updated. Please contact us with concerns and suggestions.

RES Inc.
15 Antares Dr., Suite 3B
Ottawa, Ontario, Canada
K2E 7Y9
Tel.: (613) 864-7373

To reach us: