concomitant
Meaning of concomitant: A flag for something running alongside the matter at hand, most often another illness or another drug.
Definition of concomitant
Concomitant means occurring or existing at the same time as something else. In practice it labels whatever accompanies the main subject: a concomitant medication is one a person takes alongside the treatment under discussion, and a concomitant condition is an illness present besides the one being treated. The word describes timing only, and implies nothing about cause.
Why does the word appear so often in trials?
Because a study needs a clean record of everything else going on. Someone joining a clinical trial arrives with their own illnesses and their own prescriptions, and every one of them is logged as concomitant. That list is what allows a side effect to be traced to the treatment being tested rather than to something already being taken, and it is how interactions between drugs are spotted. Protocols usually name certain concomitant medications as not permitted, because they would interfere with the drug under study or muddy the measurement, and being on one can keep a person out of the trial.
How does it differ from nearby words?
| Word | What it means |
|---|---|
| Concomitant | Present at the same time as the matter under discussion |
| Concurrent | Running at the same time, usually said of treatments |
| Comorbid | Another diagnosed illness alongside the main one |
| Adjunctive | Added deliberately to support the main treatment |
| Coincidental | Occurring together with no connection implied |
The distinction most often missed is between concomitant and adjunctive. A medication recorded as concomitant is merely present and was not chosen as part of the plan, while an adjunctive one was added on purpose to help. The same tablet can be either, depending on why it is being taken.
Where else is it used?
In treatment planning it describes therapies delivered across the same period rather than one after the other. Radiation given during a course of chemotherapy is called concomitant chemoradiation, and it differs from the sequential version in both effect and toxicity. Eye medicine gives the word a narrower technical sense, where a concomitant squint keeps the same angle between the eyes in every direction of gaze, which separates it from the kind produced by a paralyzed muscle. Reading it therefore depends on the field, although the core sense of accompanying holds throughout.
Also known as
Used in a sentence
All concomitant medications were recorded at the baseline visit.
Good to know
Concomitant records only that something is present at the same time, so the label carries no implication that the two are related or that either caused the other.
Word origin
Where “concomitant” comes from
From the Latin concomitari, to accompany, built on con-, meaning with, and comes, a companion.