Flashcards in Clinical Trial Deck (18):
Why are clinical trials important?
-Provide evidence for: medical practice and SIGN guideline or formulary and many drug treatments (I.e. for stroke, cancer, rheumatoid arthritis)
What is a problem with observation studies?
Clinical impressions of the efficacy of a drug are often misleading because of bias, the selectivity of doctors’ memories and the placebo effect
What are clinical trial?
A way of testing the efficacy of a drug can be tested and proven
It may indicate the risks involved with drug use
What does the reliability depend on?
The trial design, trial procedure and conduct and trial analysis.
What is a double blinded clinical trial?
Patient and doctor both unaware of what drugs patient is on
What is a single blinded clinical trial?
Patient unaware of what drugs they are taking but doctor is aware (stent stud)
What is a prospective clinical trial?
Protocol decided before hand
What is a retrospective clinical trial?
A drug trial where data is collected from case record after treatment is given - less good as open to bias
What is a placebo controlled study?
Equal number of subjects and one given placebo and one given active drug and then outcomes of both groups compared
What is a study of comparison with other therapy?
Equal number of subjects that were part of a drug trial and others who were part of a comparitive therapy trial and then compare outcomes of both trial
What is a cross over trial?
Two groups of equal numbers which were either part of a compared therapy or drug study and in the cross over design (after 8 week wash out period) they swap trials
What is a randomised control clinical trial?
Patients assigned at random to either treatment(s) or control
Disadvantages of randomised control clinical trial
-Subjects may not represent general patient population and are better at complying
-Twice as many new patients required for study
-Accepting that it's random: some doctors refuse (PFO closure) and some patients will refuse treatment
-Administration complexity as its random
What is a superiority design?
Shows that the new treatment is better than the control or standard
What is a non-inferiority design?
Show that new treatments:
-is not worse that standard by more then certain margin
-would have beaten placebo if a placebo arm had been included
What are possible end points in drug trials?
-No. of hospital admissions
-Lowering of blood pressure
-Compare pain control or change in mood
Stages in clinical trials
1. Drug discovery
2. Preclinical development: animal pharmacology (ADRs), toxicology (teratogenicity, mutagenicity) and tissue culture
3. Volunteer studies (phase I) pharmacology in normal volunteers (Cmax, Vd, metabolism, elimination etc)
4. Volunteers (phase II): confirm kinetic and dynamics
5. Phase III: formal trials to determine efficacy
6. Phase IV: post-marketing surveillance for evidence of safety - tested on patients