Sunday, October 26, 2008

Thalidomide

Thalidomide-related birth defects. Source: Otis Historical Archives National Museum of Health and Medicine, CC2.0 license
 

Thalidomide is an experimental drug used for life threatening illnesses. It was the center of a dangerous controversy in the 1960s when scientists discovered that pregnant women given the drug for morning sickness gave birth to babies with severe birth defects. The flipper-like appendages resulted in a slang term still known today, and led to great challenges for 10,000 children born during the late 1950s. 

 

Thalidomide was first marketed as a sedative in Europe in the 1950s. The German pharmaceutical company Gruuenthal released the drug in 1957. Thalidomide's teratogenic properties were not known at that time, and it was prescribed as a sleeping pill and anti-nausea medication to treat morning sickness in pregnant women.

A teratogen is any substance that causes fetal damage, resulting in deformities and birth defects. This troubling side effect of thalidomide was not discovered until 1961. The March of Dimes estimates that, between 1956 and 1962, 10,000 children were born around the world with stunted arms and/or legs due to their mothers taking the drug while pregnant. The FDA in the United States had reportedly refused to approve the drug until further testing was done. After the tragic discovery that the drug was more harmful than beneficial, it was banned worldwide. The drug is still not available in the U.S. outside clinical trials for the treatment of life-threatening diseases.

One of the more disturbing discoveries by scientists in the 1960s was that a single dose of thalidomide early on in pregnancy could damage the fetus. Also, in addition to limb deformities, the babies were at risk for neurological disorders, internal defects, and sensory defects. The condition of the extremities, essentially absent with stubby limbs resembling flippers in their place, gave birth to the slang term that has been used for the children born with these defects. The scientific term for the most common arm-shortening defect is phocomelia.

The surge in deformities led to a boom in the prosthetics market because new advances were needed to aid the children as they grew into adults. New pneumatic prostheses were developed, but, according to the Association of Children's Prosthetic-Orthotic Clinics, many only used them in public and turned to using their feet in private to accommodate the tasks for which their hands would be responsible. The organization published a full report on the status of the thalidomide babies in 1992.

Thalidomide is currently marketed by Celegen as Thalomid. It was initially approved by the FDA in 1996 for limited distribution in experimental testing of fatal diseases, but 1997 and 1998 saw its approval for other diseases, including Hansen's Disease, leprosy, multiple myeloma, Behcet Disease, Sjogren syndrome, lupus, and AIDS, among others.

It is still not known if thalidomide is present in the sperm of patients, and men who take experimental doses of the drug are encouraged to abstain from sex to prevent any potential pregnancy while taking the drug. Women who are taking the drug as an experimental treatment cannot continue on it if they do not abstain from sex or confirm birth control methods being used. The FDA urges that any hint of a pregnancy requires the cessation of the use of thalidomide and the discussion of possibly terminating the pregnancy due to the damage that would already have been done to the fetus.

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