Reading a reaction list
Every drug page has a reaction lookup. It is a table of the reaction terms that the reports of the drug record. This guide says what each part of the table is. The site read the FDA pages on .
The term and its plain meaning
A reaction term is a coded name, for example "Dyspnoea". FDA codes the words of a reporter with the MedDRA dictionary. The person who codes a report selects the term that agrees best with the words of the reporter.
The words under a term are the plain meaning. The site wrote them. They explain the term and add nothing to a report. A term can describe a circumstance and not a harm, for example "Drug ineffective".
The count and the share
The count is the number of reports that record the term. The share is the count as a percent of all the reports that name the drug.
One report can record many terms. So the counts add to more than the number of reports, and the shares add to more than 100 percent.
The share is a share of reports. It is not a share of people who take the drug. The data do not give that number.
What FDA says about a reaction in a report
No individual drug is connected to any individual reaction. When a report lists multiple drugs and multiple reactions, there is no way to conclude from the data therein that a given drug is responsible for a given reaction.
Source: openFDA, Drug Adverse Event Overview. The site read the page on .
Any number of the drugs may be marked as suspect if thought to be responsible for one or more of the reactions, but that information is not validated.
Source: openFDA, Drug Adverse Event Overview. The site read the page on .
A term in the list is therefore not a finding about the drug.
What the list leaves out
- A term with fewer than 5 reports is not in the list.
- The site keeps reaction terms for a year only if the drug has 12 or more reports in that year. It keeps a term that two or more reports record, and the 20 most frequent terms.
- For some drugs the site keeps terms for only a part of the reports. The page says how much, and it says when the list is not the full count of FDA.
- A count in the list can be lower than the count of FDA.
The CSV file of the page has the same rows and ends with a note that says the same.
How to find one term
Type a term, or a plain word, in the field above the table. The table shows the rows that match. The button "Show more terms" adds more rows. A term with a page links to the page of the term.
What the list is not
- It is not the list of reactions on the label of the drug. The official pages at the end of a drug page link to the labels.
- It does not rank drugs. FDA says:
Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product. Many drug products appear frequently in adverse event reports simply because they are commonly taken by many people in the population, not because they are responsible for more adverse events.
Source: openFDA, Drug Adverse Event Overview. The site read the page on .
See also What FAERS and MAUDE are and the glossary.
Last checked against FDA pages: .