Thalidomide, the drug that caused a worldwide epidemic of serious birth def
ects in the late 1950s and early 1960s, was recently approved by the U-S Fo
od and Drug Administration (FDA) for use in treating the skin disease eryth
ema nodosum leprosum, a complication of leprosy. The drug has also shown pr
omise in the treatment of other serious diseases. If thalidomide is eventua
lly approved for use in the US and other countries for treatment of disease
s more prevalent than erythema nodosum leprosum, or if use of the drug for
non-approved indications becomes widespread, hundreds of thousands of women
with childbearing ability could be treated. If this should happen, can we
prevent another epidemic of birth defects?
In an effort to prevent fetal exposures to thalidomide, the FDA mandated a
comprehensive programme to regulate prescription, dispensing and use of the
drug. The programme is designed to require registration of all participati
ng pre scribers, pharmacies and patients. It also requires use of effective
methods of contraception and periodic pregnancy testing of all patients wi
th childbearing ability during treatment. Prescribers are directed to couns
el both female and male patients on the risks, benefits and proper use of t
he drug, as well as on the proper use of contraceptives during treatment. T
he patient is required to sign an informed consent form before beginning tr
eatment. Prescription and dispensing of thalidomide will be tightly control
led. A thalidomide registry will monitor prescription, dispensing and use o
f the drug, and will investigate all reported fetal exposures.
This mandatory, but untested, programme promises to be effective at prevent
ing fetal exposures to thalidomide, provided that patients, prescribers and
pharmacists comply with all of its provisions. However, even if the progra
mme proves to be successful in the US, there is concern that thalidomide ma
y eventually be widely used in countries that may not require such stringen
t controls. In Brazil, where thalidomide is commercially available for trea
tment of leprosy patients, 33 cases of thalidomide embryopathy have already
been reported in the literature. Even in countries that may tightly regula
te the distribution and use of thalidomide, some patients may obtain the dr
ug through black market sources. Should these events occur, many cases of t
halidomide-induced birth defects could appear. There fore, there is a need
to develop nonteratogenic analogues of thalidomide that can provide effecti
ve treatment for erythema nodosum leprosum and other serious conditions wit
hout increasing the potential for another epidemic of thalidomide-related b
irth defects.