Concomitant Medication

Concomitant medications are the drugs and supplements a participant is taking along with the study intervention. These include prescription and over-the-counter drugs. The participant may take the concomitant medication for the same or another indication as the study intervention, such as taking an as-needed dose of an NSAID while being given an investigational biologic for rheumatoid arthritis.

This information is usually elicited along with the medical history during the screening process. A review of the concomitant medications is important to evaluate which medication may interfere with the study or intervention and may be the reason to exclude an individual from participating in a study due to known interactions. In addition to this, the concomitant medication can lead to faulty conclusions regarding the safety and efficacy of the trial or may interfere with the pharmacokinetics of the investigational drug and increase the risk of adverse effects.

Source: NIA Glossary of Clinical Research Terms. (n.d.). National Institute on Aging. Retrieved January 8, 2022, from