In the 1960s the drug thalidomide was used by some pregnant women in Europe and Canada
to treat morning sickness. Women who took the drug in early pregnancy gave birth to
children with severe birth defects such as missing or shortened limbs. Shortly after the
birth defects were observed, thalidomide was banned worldwide. It has recently been
discovered that thalidomide is effective in treating symptoms of diseases such as leprosy
and possibly AIDS. The state of California has identified thalidomide as a developmental
hazard, which means there is proof that it may harm unborn children. However, thalidomide
was approved in 1998 by the U.S. Food and Drug Administration (FDA) to treat leprosy. In
order to avoid tragic birth defects, the FDA has established several restrictions. Doctors
prescribing and pharmacists dispensing thalidomide are required to participate in a
program sponsored by the drug's manufacturer, and patients must also be educated about the
drug's effects. Female patients must be tested for pregnancy before and while taking the
drug and must use two forms of birth control if sexually active. Men taking thalidomide
must also practice birth control because it is not known if thalidomide can produce
defects in the children they conceive. Donating of blood or semen and breast feeding are
prohibited while taking the drug.
In Europe and Canada during the early 1960s, thalidomide was prescribed to treat
morning sickness in pregnant women. At that time, it was not approved in the United States
because Dr. Frances Kelsey from the Food and Drug Administration (FDA) stated there was
insufficient proof of the drugs safety in humans. Thalidomide was soon banned
worldwide when it was discovered that it caused tragic birth defects. According to the
March of Dimes (http://www.marchofdimes.com/alcohol_thalidomide.html, "More than 10,000 children around the world were born with major
malformations, many missing arms and legs, because their mothers had taken the drug during
early pregnancy. Mothers who had taken the drug when arms and legs were beginning to form
had babies with a widely varying but recognizable pattern of limb deformities. The most
well-known pattern, absence of most of the arm with the hands extending flipper-like from
the shoulders, is called phocomelia. Another frequent arm malformation called radial
aplasia was absence of the thumb and the adjoining bone in the lower arm. Similar limb
malformations occurred in the lower extremities. The affected babies almost always had
both sides affected and often had both the arms and the legs malformed. In addition to the
limbs, the drug caused malformations of the eyes and ears, heart, genitals, kidneys,
digestive tract (including the lips and mouth), and nervous system. Thalidomide was
recognized as a powerful human teratogen (a drug or other agent that causes abnormal
development in the embryo or fetus). Taking even a single dose of thalidomide during early
pregnancy may cause major birth defects."
In 1998 the Food and Drug Administration (FDA) approved thalidomide for use in treating
leprosy symptoms (FDA). Studies are also being conducted to determine the effectiveness
of thalidomide in treating symptoms associated with AIDS, Behchet disease, lupus, Sjogren
syndrome, rheumatoid arthritis, inflammatory bowel disease, macular degeneration, and some
cancers (MOD, November 1998).
The California Environmental Protection Agency (Cal/EPA) has added thalidomide to its
Proposition 65 list of developmental toxins. This means there is evidence that the
compounds can be harmful to unborn children (Cal/EPA
Proposition 65 List).
The Food and Drug Administration (FDA) approved thalidomide for treatment of leprosy
symptoms in 1998 (FDA). The approval was based upon the establishment of strict
safeguards to prevent the occurrence of birth defects. The March of Dimes has summarized
the FDA restrictions and the following information comes from their web site (MOD, November 1998):
To prevent fetal exposure to thalidomide, the drugs manufacturer has developed
the System for Thalidomide Education and Prescribing Safety (STEPS) program. Only
physicians who are registered may prescribe thalidomide to patients and those
patientsboth male and femalemust comply with mandatory contraceptive measures,
patient registration and patient surveys.
Thalidomide may be dispensed only by licensed pharmacists who are registered in the
S.T.E.P.S. program and have been educated to understand the risk of severe birth defects
if thalidomide is used during pregnancy.
In addition, female patients prescriptions will not be filled without a
physicians written report of a negative pregnancy test that has been conducted
within 24 hours of starting thalidomide therapy. Pregnancy testing will continue to be
required weekly during the first month of use, then monthly thereafter in women with
regular cycles, or every two weeks if cycles are irregular. Prescriptions are only for one
months supply. A female patient must abstain from sexual intercourse or use two
highly effective methods of birth control at the same time for at least one month before
receiving thalidomide and continue their use until one month after the last thalidomide
dose. All patients must participate in a mandatory registry that will provide follow-up to
detect any adverse effects of using thalidomide and will hopefully identify areas in which
safeguards need to be improved, if problems occur.
The FDA reminds female patients that no method of birth control is completely reliable,
except for having no sexual intercourse at all (abstinence). Women being treated with
thalidomide should refrain from any other activities that could result in pregnancy, such
as assisted fertilization methods. Breast feeding a baby and donating blood are also
Male patients must abstain from sexual intercourse or use a condom during intercourse
while taking thalidomide and for one month after, because it is not known if thalidomide
in semen is a hazard. Donating sperm or blood is also prohibited.
It is vital that each patient understands that thalidomide is prescribed for him or her
alone and must not be shared with, or given to, others.
The following information about thalidomide research comes from the March of Dimes web
site (MOD, November 1998):
One of the manufacturers of thalidomide has an ongoing program to develop and study the
effectiveness of thalidomide analogs chemical compounds that may have
thalidomides benefits without its toxic and teratogenic effects. Some of these
compounds should be ready for clinical testing soon.
March of Dimes has recently supported thalidomide research on the stubborn question of
how the drug causes a wide range of birth defects, depending greatly on just when a woman
takes it during her pregnancy. Learning how its mechanisms work should give us insight
into the major processes of normal development and how drugs or other chemicals can
US Food & Drug
Administration - Center for Drug Evaluation and Research: Thalidomide Information
News (UK) - "Fresh Start for Notorious Drug"
Thalidomide - Contergan®
- Detailed information on thalidomide and a collection of links to
interesting web resources.