myocardial infarction or death from CAD in postmenopausal women either with or without known heart disease. HRT also didn't reduce how rapidly blockages in the arteries of the heart associated with CAD got worse.
In fact, some studies found HRT might increase risk to the heart, especially in the first year after this therapy was started. The W omen's H ealth I nitiative (WHI) study randomized 16,608 postmenopausal women between 50 and 79 years of age without known CAD to receive either an estrogen- medroxyprogesterone combination as HRT, or placebo. The women who received HRT had a 24% higher risk of having a myocardial infarction or dying from CAD than those receiving placebo.[14]
Another group of 10,739 women in WHI who'd previously had a hysterectomy were randomized to either estrogen therapy alone or placebo. In these women, treatment with estrogen showed no significant benefit or harm regarding CAD compared to placebo, but it was associated with an increased risk of stroke.[15]
Current guidelines recommend that HRT should not be used in postmenopausal women to prevent heart disease.[16] Here again, an idea that was once conventional wisdom and supported by preliminary research was not confirmed by further studies.
But the final word on this subject might not have been written yet. It's been suggested that giving HRT to younger postmenopausal women, such as those ages 50 to 59, or using a lower dose of estrogen in women age 60 or older may not be associated with increased cardiovascular risk and might still turn out to have a protective effect regarding CAD. HRT can also have good and bad effects on other parts of the body. Potential benefits include preventing osteoporosis (thinning of bones) and treating symptoms associated with menopause, such as “hot flashes.” Possible risks of HRT with an estrogen-progestin combination include increasing the chance of getting breast cancer. The overall decision whether or not to use HRT in individual postmenopausal women remains complex and hopefully will be clarified by further research.
* * * *
Pills and Pregnancy
A dramatic example of how inadequate research can result in tragedy involves a woman's use of medications during preg- nancy. Both the mother and the developing baby (called an embryo from about the first four days through the eighth week after conception, and afterward a fetus until birth) share a single blood supply. During most of pregnancy, blood and nutrients are supplied to the baby through the placenta (specialized tissue attached to the inner wall of the uterus) and the umbilical cord. If the mother takes a medication, the baby can, to some degree, receive it too.
Thalidomide is a medication marketed from the late 1950s through 1961 as a treatment for morning sickness and a sleeping aid for pregnant women.[17] However, by 1961 it was belatedly recognized that use of thalidomide was associated with a high risk of serious birth defects in children born to women who'd taken it. These included severe shortening of the arms and legs—"phocomelia,” in which the hands or feet are connected to the trunk by only abnormally short or even absent long bones.
Over 10,000 children affected by thalidomide-induced malformations were born worldwide. An application to market thalidomide in the United States was submitted to the FDA in 1960. However, the physician who reviewed the application, Frances Kelsey, delayed approval pending further evaluation of the drug's safety and effectiveness. Because of her concerns, thalidomide didn't become available for general use in the United States before its “teratogenic” (birth defect-producing) effects were recognized.
As a result of these events, the FDA received increased authority and responsibility to ensure that drugs were both safe and effective. The thalidomide tragedy also showed that an idea commonly held before then, that medications given to the mother did not cross the placenta to her embryo or fetus, was
In fact, some studies found HRT might increase risk to the heart, especially in the first year after this therapy was started. The W omen's H ealth I nitiative (WHI) study randomized 16,608 postmenopausal women between 50 and 79 years of age without known CAD to receive either an estrogen- medroxyprogesterone combination as HRT, or placebo. The women who received HRT had a 24% higher risk of having a myocardial infarction or dying from CAD than those receiving placebo.[14]
Another group of 10,739 women in WHI who'd previously had a hysterectomy were randomized to either estrogen therapy alone or placebo. In these women, treatment with estrogen showed no significant benefit or harm regarding CAD compared to placebo, but it was associated with an increased risk of stroke.[15]
Current guidelines recommend that HRT should not be used in postmenopausal women to prevent heart disease.[16] Here again, an idea that was once conventional wisdom and supported by preliminary research was not confirmed by further studies.
But the final word on this subject might not have been written yet. It's been suggested that giving HRT to younger postmenopausal women, such as those ages 50 to 59, or using a lower dose of estrogen in women age 60 or older may not be associated with increased cardiovascular risk and might still turn out to have a protective effect regarding CAD. HRT can also have good and bad effects on other parts of the body. Potential benefits include preventing osteoporosis (thinning of bones) and treating symptoms associated with menopause, such as “hot flashes.” Possible risks of HRT with an estrogen-progestin combination include increasing the chance of getting breast cancer. The overall decision whether or not to use HRT in individual postmenopausal women remains complex and hopefully will be clarified by further research.
* * * *
Pills and Pregnancy
A dramatic example of how inadequate research can result in tragedy involves a woman's use of medications during preg- nancy. Both the mother and the developing baby (called an embryo from about the first four days through the eighth week after conception, and afterward a fetus until birth) share a single blood supply. During most of pregnancy, blood and nutrients are supplied to the baby through the placenta (specialized tissue attached to the inner wall of the uterus) and the umbilical cord. If the mother takes a medication, the baby can, to some degree, receive it too.
Thalidomide is a medication marketed from the late 1950s through 1961 as a treatment for morning sickness and a sleeping aid for pregnant women.[17] However, by 1961 it was belatedly recognized that use of thalidomide was associated with a high risk of serious birth defects in children born to women who'd taken it. These included severe shortening of the arms and legs—"phocomelia,” in which the hands or feet are connected to the trunk by only abnormally short or even absent long bones.
Over 10,000 children affected by thalidomide-induced malformations were born worldwide. An application to market thalidomide in the United States was submitted to the FDA in 1960. However, the physician who reviewed the application, Frances Kelsey, delayed approval pending further evaluation of the drug's safety and effectiveness. Because of her concerns, thalidomide didn't become available for general use in the United States before its “teratogenic” (birth defect-producing) effects were recognized.
As a result of these events, the FDA received increased authority and responsibility to ensure that drugs were both safe and effective. The thalidomide tragedy also showed that an idea commonly held before then, that medications given to the mother did not cross the placenta to her embryo or fetus, was
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