If the patient is receiving a "concomitant" medicinal drug (prescribed to the patient by another physician), and the radiologist performing the imaging procedure is unaware of this, potentially harmful side-effects can occur and increase the risk of contrast medium-induced nephropathy (i.e. increase the risk of damage to the kidneys).
In general, radiologists carefully ask their patients about other medicinal drugs they are "concomitantly" taking before the imaging procedure.
Whether concomitant drug abuse leads to an increased number of deaths was scientifically analysed in Sheffield, UK.
The authors showed that at least in the Sheffield area, intravenous (IV) administration of an opiate is the most consistent factor associated with drug abuse deaths.
The co-administration of a concomitant drug of misuse appeared to be a feature rather than a risk factor per se in such deaths.