McKenna's Pharmacology for Nursing, 2e

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P A R T 7  Drugs acting on the reproductive system

■■ BOX 40.3  Contraceptives: Forms and dosing (continued)

Injectables Depo-Provera

Vaginal ring NuvaRing

150 mg medroxyprogesterone, given by deep IM injection q 3 months 150 mg medroxyprogesterone, given by deep IM injection q 3 months

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

Depo-Ralovera

Intrauterine device Mirena

Subdermal implant Implanon NXT

52 mg levonorgestrel: inserted into the uterus; releases low-dose levonorgestrel over a 5-year period

68 mg etonogestrel implanted subdermally, effective up to 3 years, may be replaced at that time if desired

The evidence

BOX 40.4

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.

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 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. would not even consider it. APPLYINGTHE EVIDENCE

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.