Thalidomide is also used as a cancer treatment, where its property of
stopping new blood vessel growth is not a downside but a desired
effect. Massive precautions are taken.
On Tue, Mar 24, 2020 at 02:24:53PM -0500, Terry McCreary wrote:
Off-topic (though there seems to be a lot of that about :))
There is a thorny problem with thalidomide. If the L-form is
administered, the body converts some of it to the D-form. (Which means
that even if the L-form had been isolated and administered, birth
defects would still have occurred.) That would seem to be the end of
discussion, except that it turns out that thalidomide is also useful in
treating leprosy. Which occurs largely in less-developed countries...
So the choices for medics in those countries are: don't provide
thalidomide at all, and leprosy must be treated with other drugs;
provide thalidomide only to those who agree to sterilization; provide
thalidomide without requiring sterilization, producing more birth
defects. The second choice is obviously best, but education in that
situation is...difficult, to say the least. :(
Best -- Terry
On 3/24/2020 2:04 PM, Barry Jolly wrote:
Thalidomide is a stereo isomer meaning it has two forms for the same--
molecule, a dextro-rotary form and a levo-rotary form. Dextro-rotary
isomers rotate plane polarized light to the right and levo-rotary
forms rotate plane polarized light to the left. Take a look at your
hands and you will see that both are hands but they will not
superimpose on each other. This is the idea in stereo compounds.
When thalidomide was first synthesized it was a mixture of both
isomers in a form called a racemic miixture and included both dextro-
and levo-rotary forms of the isomer. The human body prefers
levo-rotary compounds by nature. At the time thalidomide was
synthesized, researchers did not know how to chemically separate a
racemic mixture of stereoisomers. Thus, the drug thalidomide was
administered to patients in its racemic form. Later research proved
the dextro-rotary form of thalidomide produced child deformities while
the levo-rotary form did not. As chemistry separation techniques
advanced it became possible to separate the thalidomide isomers into
relatively pure compounds. I do not know if thalidomide is useful
today. This whole area of separating stereo-compounds is still a
problem for chemists today. In fact, my chemistry professor was
trying to develop a resin that would filter and separate racemic
mixtures. He never succeeded. Probably a Nobel prize awaits the
chemist who succeeds
Barry
Thalidomid ( initially known as "DE:Contergan" )
was marketed as a Sedative drug
prescribed for
Sleeping problems
Morning Sickness
the later was what screwed the pooch.
What turned it FUBAR was ignoring
upcoming deformation in babies.
Uwe
Dr. Terry McCreary
Professor Emeritus
Murray State University
Murray KY 42071