Clinical Trials

Description of how clinical trials are held, including the placebo effect and ethics of clinical trials.

HideShow resource information
  • Created by: Dilly
  • Created on: 07-06-12 07:25
Preview of Clinical Trials

First 447 words of the document:

Clinical Trials are the last stage of a long and expensive new drug development
Today, our main reasons for running clinical trials are to make sure that our drug
Is safe to give to patients
Actually does what we claim
A pharmaceutical company must demonstrate both of these before it can obtain a
licence which allows it to sell the drug to doctors and hospitals. It's the law! We may
also discover new unexpected actions of our test drug e.g., a drug may be
developed as a muscle relaxant but clinical trials show that it is also an excellent
analgesic (painrelieving drug).
We need clinical trials when we are
Putting a new drug on the market for the first time.
Changing the illness or condition we are treating.
Changing the route of administration e.g., from tablet by mouth to intramuscular
Changing the dosage form of a drug e.g., from tablet to liquid suspension.
Continuing to monitor drug safety after a drug has been launched on the market.
What are we looking at? A clinical trial looks at a small proportion (sample) of the
total population (all patients) with the same condition or illness and tries to estimate
how well our drug will work in all patients. For this reason we must design them and
look after them very carefully so that we produce good data and meaningful results.
The term Clinical Trial implies that the studies involve patients (people with a
disease or medical condition that needs treatment), but sometimes the term is used
to describe any study on people.
Drugs are developed in a stepwise manner, passing through a number of
Phases from first introduction into people to the final test for effects in large
numbers of patients:
Phase I ­ Healthy volunteer studies (first administration to man).
Phase II ­ First administration to patients (first administration to man for toxic
Phase III ­ Pivotal Studies: Large scale studies in patients to confirm safety &
Phase IV ­ Continued research, expansion of indications, safety followup etc.
Clinical trials are very carefully controlled at every stage, including background,
methods, how we will choose which patients to include and exclude from the study,
all tests and analyses, drug labelling, ethics committee and legal information.
Special rules called Good Clinical Practice (GCP) must be followed and these
ensure that everything is done consistently and to the highest standard.

Other pages in this set

Page 2

Preview of page 2

Here's a taster:

Placebo: If we want to know how well our drug works we must compare it to an
inactive drug, placebo. This is important because our expectations can lead to real
results e.g., if a doctor gives a group of patients tablets and tells them it will cure
their headache, a number of patients will get better, even though the tablet is only
made of chalk and has no active ingredient. This is called the placebo effect.
Bias: We must also remove bias wherever possible.…read more

Page 3

Preview of page 3

Here's a taster:

In this study, we can see that our test drug (solid line) is better at reducing
pain (lower pain score) than placebo (dotted line) after 5 days. There is some
improvement at Day 4 but the error bars above and below each data point tell us
that there is a real difference between the 2 treatments. At Day 5, there is no
overlap of these error bars.…read more


No comments have yet been made

Similar Biology resources:

See all Biology resources »See all resources »