March 02, 2019 Saturday
Bedtime Story
Phase I and II of Clinical Research
Whole moving from phase 0 to phase 1 the
shift is made in the study of the drug from its pharmacokinetical properties to
the study of its pharmacodynamics.
Pharmacodynamics is the study of
biochemical and physiological affect of any drug either on a single organism
say in a case of new potential cardiac drug or on multiple organisms as in the
case of a new antibiotic where the interest on the affect of drug is at both
the organism that has been infected and the pathogenic microbes that are the
source of infection.
While the stage of study of
pharmacodynamics has been initiated in phase 1 the focus is more on its
toxicity rather than its efficacy.
This means that the phase 1 of the clinical
research is essentially a test whether the drug or the molecule is safe to be
taken to the next phase of the drug research.
Once the drug gets safety clearance from
the phase 1 phase 2 is initiated which involves recruitment far greater number
of volunteers (in the range of over 200 but it depends on the type of disease and
various other factors) and this time the volunteers are not the healthy ones.
This is the first serious step of the
clinical research where the volunteers are actually the target patients with
specific disease and the drug that is tested on them is at the therapeutic
levels or at least the level at which it is believed to assert its therapeutic
effect.
This is one of those stages where almost
70% of the drugs that are ever tested in clinical research are left discarded
since either they fail to show their desired and sufficient therapeutic benefit
or the toxicity figures begin to get alarming.
Bear in mind that in phase II unlike in the
previous two phases full therapeutic dosages of molecule being tested are being
used on diseased volunteers and that would naturally take its toll.
Of the 30% drugs that do manage to go past
the phase II and end up landing in the phase III are still not presumed to be therapeutically
active.
It simply shows that the molecule is
capable of being therapeutically beneficial.
Therapeutical efficacy of the drug would be
proven in the later stages of the clinical research.
The phase III is a whole new game where a
very large number of patients with targeted diseases are recruited.
Phase III is a serious and expensive affair
as I found out through my personal experience at least in the United States.
The patient number can often run into
thousands and it is also possible for the Phase III to be carried out in more
centers than just one.
To conduct this stage not just clinical
researchers are recruited but also physicians are kept for direct supervision
of patients and their records.
Depending on the type of drug that is being
tried the volunteers are often recruited as in-patients (meaning they are
admitted) with continuous round-the-clock monitoring.
Stay tuned to the voice of an
average story storytelling chimpanzee or login at http://panarrans.blogspot.com
Good night Mon Ami and my fellow cousin ape.
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Another great educator and a teacher that I am aware of is
Professor Subhashish Chattopadhyay in Bangalore, India.
While I narrate stories, Professor Subhashish an electronic
engineer and a former professor at BARC, does and teaches real mathematics and
physics.
He started the participation of Indian students at the
International Physics Olympiad.
Do visit him here:
All his books can be downloaded for free through this link:
For edutainment and English education of your children, I
recommend this large collection of Halloween Songs for Kids:
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