612
P A R T 7
Drugs acting on the reproductive system
Injectables
Depo-Provera
150 mg medroxyprogesterone, given by
deep IM injection q 3 months
Depo-Ralovera
150 mg medroxyprogesterone, given by
deep IM injection q 3 months
Intrauterine device
Mirena
52 mg levonorgestrel: inserted into the
uterus; releases low-dose levonorgestrel
over a 5-year period
Vaginal ring
NuvaRing
0.12 mg etonorgestrel, 0.015 mg
ethinyl-oestradiol ring inserted
vaginally once a month and kept in
place for 3 weeks; after 1-week rest,
a new ring is inserted
Subdermal implant
Implanon NXT
68 mg etonogestrel implanted
subdermally, effective up to 3 years,
may be replaced at that time if desired
■■
BOX 40.3
Contraceptives: Forms and dosing
(continued)
Menopause and hormone replacement therapy (HRT)—The Women’s Health Initiative
Women experience the menarche (onset of the menstrual
cycle) in adolescence and menopause (cessation of the
menstrual cycle) in midlife.The age at which a woman
experiences menopause or “the change” of life varies.
The family history of onset of menopause is a good
guide for when the effects can be expected. Just as the
physical changes associated with puberty can take a
few years to be accomplished, so too can the changes
associated with menopause.The signs and symptoms of
menopause (vaginal dryness, hot flushes, moodiness, loss
of bone density, increased risk of cardiovascular disease,
somnolence) are related to the loss of oestrogen and
progesterone effects on the body.
HORMONE REPLACEMENTTHERAPY OR NOT?
For centuries, women have proceeded through this
time in their lives without pharmacological intervention,
although many herbal and alternative therapies may help
to ease the transition through menopause (see Box 40.5).
Women who rely on these therapies need to be cautioned
about potential drug–drug interactions and advised to
always report the use of these agents to their healthcare
providers.Today, with more research and safer drugs
available to counteract some of the effects of menopause,
many women choose to use HRT if the adverse effects
of menopause become too uncomfortable or difficult to
tolerate.The use of HRT can decrease the discomforts
associated with menopause, although various forms of
HRT have been associated with increased risks of breast
and cervical cancer. Many women are reluctant to consider
HRT because of these effects.The newer drugs used in HRT
have been shown to be associated with only a possible
increase in risk of breast and cervical cancer, but with
long-term use, they are associated with an increased risk
of cardiovascular events. Women with many risk factors
for developing these cancers are at greater risk than
women with no risk factors. Other drugs—the oestrogen
receptor modulators—have anti-oestrogen effects on the
breast and may remove the cancer risk. However, these
drugs may be less reliable in their management of the
signs and symptoms of menopause and have not been
correlated with a reduction in the risk of coronary artery
disease.
EARLY RESEARCH
TheWomen’s Health Initiative was a long-term, multisite
study of the effects of hormones on menopausal women.
When the initial reports were published, after the third
and fourth years of the study, it seemed that the use of
HRT was protective in many ways. It seemed that women
using HRT had decreased coronary artery disease and
cardiovascular events, decreased osteoporosis and
bone fractures, decreased breast and colon cancer, and
improved memory. HRT was then being prescribed to
prevent a number of these chronic conditions.
LATER RESEARCH
In 2002, however, the study was stopped when it was
found that women using HRT for 5 or more years had an
increased incidence for cardiovascular disease and stroke,
as well as blood clots, gallstones and ovarian cancer.
The news headlines were confusing at best; many women
simply stopped HRT, and women new to menopause
would not even consider it.
APPLYINGTHE EVIDENCE
The woman who is entering menopause should have all
of the information available before deciding whether HRT
is for her.This can be a very difficult decision for many
women, because the risks involved may outweigh the
benefits or vice versa.The nurse and midwife are often in
the best position to provide information, listen to concerns
and help the woman to decide what is best for her.
A complete family and personal history of cancer and
coronary artery disease risk factors should be completed
to help the woman balance the benefits versus the risks
of this therapy. If the decision is made to use HRT, the
woman may need support in dealing with the effects of the
drugs and may have to try several different preparations
before the one best suited to her is found.This can be a
very frustrating time, so the woman will need a consistent,
reliable person to turn to with questions and for support.
As researchers continue to study women’s health issues,
better therapies may be developed to help women through
this transition in life. Keeping up with the research as it is
reported can be a difficult task, but for anyone who works
with women in clinical practice it is a necessity.
The evidence
BOX 40.4
