Thalidome is a drug which caused a lot of controversy in the 1970's. It was meant to be a tranquilizer but there was no knowledge of its side effects until every pregnant woman who took the drug began to give birth to severely deformed children. This even inspired a cult classic movie back in the 1970's about a "monster baby" whose mother was presumably taking the medication while she was pregnant. That aside, the drug was immediately removed once it was connected to the deformity of so many children.
However, it has been also found that Thalidome is highly effective in the CURE of some strains of the bacteria which causes leprosy, which could be a solution for many third world countries who are still suffering from this infesting disease. Moreover, the drug is also effective in reducing the effects of body rejection in cases of bone marrow transplant: It looks like the drug can actually prevent the effects of Grafts vs Host (GVHD).
What is under consideration at the moment is the potential use of the drug to treat these types of cases as long as there is 100% certainty that the patient is not pregnant. Therefore, the case of Thalidomine is basically that what once was considered to be a source of destruction is now seen under a new light of scientific hope.
The thalidomide case refers to the two different isomers of thalidomide that are known to exist. An isomer exists when there are either different molecular structures or different arrangements of the atoms for compounds with the same chemical formula. In the case of thalidomide, the compound is racemic. This means that it equally contains both left- and right- handed isomers. The right-handed isomer is an enantiomer and is an effective drug against morning sickness; however, the left handed isomer is teratogenic. Teratogens can cause structural abnormalities and it is for this reason that its use is highly controversial. If it is taken during pregnancy there is a high risk of birth defects in the developing fetus.