PubMed® and the Expansion of Pharmacological Action Terms
the ability to search for Pharmacological Action (PA) terms was introduced in PubMed in 2003. See the article Nahin AM. Pharmacologic Action Headings: PubMed®. NLM Tech Bull. 2003 Jul-Aug;(333):e6. for background information and to learn how this feature facilitates searching for drugs and chemical substances with particular actions (see also How to Search Using PA Terms below.)
Up until this year, the lists of drug and substance terms used for PA searches included only terms identified in MeSH as having that action (see Figure 1).
Earlier this year, the lists used by PubMed were revised. (See a sample list.) Now, the lists may include terms with a Pharmacological Action that is an indention of the "list" term in the MeSH hierarchy. An example is the drug Amitriptyline. This heading is assigned the PA, Antidepressive Agents, Tricyclic which is an indention of Antidepressive Agents in the hierarchy of MeSH headings (see Figure 2).
Amitriptyline and all other terms with a PA of Antidepressive Agents, Tricyclic, or Antidepressive Agents, Second-Generation (also an indention of Antidepressive Agents) are included on the list for the PA Antidepressive Agents (see Figure 3).
Figure 3: Portion of list of terms for the PA search Antidepressive Agents pointing out the actual PA assignment for some terms.
Some headings are never designated as the PA of a drug or chemical because they are too broad for that usage. They are useful for grouping drugs and chemicals with more specific (indented) PAs. An example of this is the PA search term Autonomic Agents. No terms in MeSH have been assigned this PA but its indented terms, e.g., Antiemetics; Bronchodilator Agents, are true PAs. Therefore, to allow for broad retrieval we have a PA search for Autonomic Agents which includes all the drugs and chemicals that have been identified as having the actions of Antiemetics; Bronchodilator Agents, etc.
In summary: there are now more PA terms for searching and retrieval is more comprehensive.
- Use the [pa] search tag, e.g., caustics [pa].
- Each PA term has an entry in the MeSH database, where you can use the Links menu to do a PA search (see Figure 4).
- Use the link from the name of the PA to see the list of drugs and chemicals included in the search.
- Note: If a PA term is entered without a search tag, PubMed will search the term as in this example using Caustics:
- "caustics"[MeSH Terms] OR "caustics"[Pharmacological Action] OR caustics[Text Word]
The list of all Pharmacological Action terms is available in the MeSH database.
Nahin AM. PubMed® and the Expansion of Pharmacological Action Terms. NLM Tech Bull. 2007 Nov-Dec; (359):e5.