During my recent work I came across 2 cases of usage of restricted medications in patients participating in clinical trials. In both cases restricted medications were prescribed by GP or physician at local hospital without realising that patients should not take these medications. Just to put your mind at rest both patients are well, but what happened is something that everyone in clinical research should be concerned about.

But let’s start with what is restricted medication and why such medications exist? 

All medications are metabolised in specific parts in the human body (in most cases liver is involved) and sometimes some medications can influence (increase or decrease) the plasma concentration of other medications. This could be potential safety issue for the patient as they could be exposed to overdose or lower than the required therapeutic dose. So it is understandable that such medications would be considered “restricted”. This is, of course, the simplest explanation.

Why restricted medications are very important in clinical trials?

As we know clinical trials drugs are newly developed compounds and there are lots of unknown about them. While they are in clinical trials it is important that patients do not take “restricted medications”, which could affect the plasma concentration of the study medication because this could be significant safety issue.

Then how these 2 cases happened and patients were prescribed restricted medications?

The discussion below is relevant to UK and I have to admit I am not familiar how health care systems around the world operate. In a perfect world all health care providers will have access to patients’ electronic medical records and they will be able to obtain the most up to date information. Unfortunately the world is not so perfect and each health care provider in UK has their own EMR or paper records that other providers do not have access to. This means that, more or less, we rely on patients to provide adequate information to different health care providers. However this is not a solution to the problem because patients cannot be expected to be able to explain what medications they should not take. 

How to avoid “restricted medications” to be prescribed to patients on clinical trials from third parties?

The only possible option that the research team has is to ask their patients to contact them if they have medications prescribed by GP or local hospital so that they can advise them if they can take them. Although this again puts the focus on patients communicating to different providers this is still less complicated solution to the problem. 

What is the big safety issue?

While patients participating in clinical trials are monitored closely and although such cases are not unusual research teams are able to react adequately to guarantee patients’ safety. The question is who is monitoring all these licensed medications on the market that have restricted medications too? 

Author: Olga Peycheva

Olga is a clinical research professional who has been working in clinical research since 2005. She has extensive experience in clinical research in Eastern and Western Europe. 

Originally published on 2 May 2017