Thalidomide is a sedative medication that was formerly used in treating morning sickness and as a sleep aid. It was sold in the late 1950′s until it was discovered that it caused birth defects. It is currently being used under the trademark Thalomid to treat multiple myeloma in combination with other drugs, with very strict controls on usage in order to avoid birth defects. It is currently being researched for treating other types of cancer and disorders, although it remains a controversial drug.
Soon after the drug gained widespread use, cases of birth defects became apparent. Many babies were born with a defect called “phocomelia” or sealed limb. This is a defect in which the babies are born with arms that resemble flippers. The longest arm bones do not develop, but sometimes fingers emerge directly from the shoulders.
The drug was banned in 1962 after many cases came to light in popular magazines and newspapers. Unfortunately, by this time over 10,000 mostly European children had been born with Thalidomide-caused birth defects.
Why it caused defects
In spite of its notoriety, the actual causes of Thalidomide birth defects went unknown for several decades. Clearly this was a drug to be avoided, but what exactly was it about this drug that made limbs fail to grow properly?
Only recently have scientists begun to understand the causes behind the defects. And in the process they have shed light on how limbs develop in the first place. They hope that these discoveries will help heal people in the future.
Although Thalidomide is harmful to developing embryos, it can be a very useful drug for treating diseases like cancer and leprosy. If scientists can decipher what makes is harmful for embryos, they may be able to produce safer forms of the drug.
Researchers began by testing the drug on chick embryos. After injecting Thalidomide into them, they discovered that a byproduct of the drug produced chicks with undeveloped wings. Within minutes of the injections, they found that blood vessels began dying. It was suspected that this kept the limbs from extending properly.
They also found that the drug disabled certain proteins responsible for healthy limb development. Research continues to find the exact mechanisms responsible for the defects. The search will then be focused on finding ways to engineer the drug so that it does not cause these types of effects.
Scientists continue to look at ways Thalidomide can be used to treat a variety of diseases and conditions. For example, it is known that the drug is useful in lowering the production of cells that cause inflammation — a culprit in the development of numerous disease processes. Lowering inflammation can be helpful in people with inflammatory disorders like lupus, rheumatoid arthritis, and some skin diseases.
Thalidomide also shows promise in treating some types of HIV-related conditions. Doctors are able to prescribe it for off-label use in treating ulcers caused by HIV, although it still has not been approved by the FDA. The drug might also prove helpful in treating Kaposi’s sarcoma — a type of cancer frequently seen in patients with HIV. Weight loss in HIV patients is yet another area where Thalidomide may prove to be an effective treatment.