|
Medical Health Encyclopedia
Menstrual Disorders - Medications
(Page 5)
Irregular break-through bleeding can occur for the first 6 months, but afterward 80 - 90% reduction in blood loss has been reported. The LNG-IUS may increase the risk for ovarian cysts, but such cysts usually cause no symptoms and resolve on their own.
Injections (Depo-Provera). Depo-Provera uses a progestin called medroxyprogesterone. Unlike users of the implants, most users of Depo-Provera stop menstruating altogether after a year. It may be beneficial for women with heavy bleeding, severe cramps, or both. Women who eventually want to have children should be aware that Depo-Provera can cause persistent infertility for up to 22 months after the last injection, although the average is 10 months. Weight gain can be a problem, particularly in women who are already overweight. Women should not use Depo-Provera if they have a history of liver disease, blood clots, stroke, or cancer of the reproductive organs. [For more information, see In-Depth Report #91: Contraceptives.]
Hormones Used in Contraceptives
Estrogen (Estradiol)
Estrogen is the major female hormone and is responsible for female characteristics. The estrogen compound used in most oral contraceptives is estradiol and is always used with a progestin.
Effects on Reproduction. When used throughout a menstrual cycle with progesterone, it suppresses the actions of other reproductive hormones (luteinizing hormone, or LH, and follicle stimulating hormone, or FSH) and prevents ovulation. Estrogen also changes the cellular structure of the lining of the uterus (the endometrium) and hinders implantation of a fertilized egg.
Side Effects of Estrogen. During the first 2 to 3 months of oral contraceptive use, side effects from estrogen in the combined pill include:
- Nausea and vomiting. (Can often be controlled by taking the pill during a meal or at bedtime.)
- Headaches. (In women with a history of migraines, they may worsen.)
- Dizziness.
- Breast tenderness and enlargement. Studies have been conflicting about whether estrogen in oral contraception increases the chances for breast cancer, and if it does, which women are at risk. Several studies have found no evidence that OC use increases the risk for breast cancer. Still, more research is needed.
- Estrogen has mixed effects on heart. It may improve cholesterol and other lipid levels. However, it also increases blood clotting and can increase the risk for stroke in certain women, especially smokers. New OC preparations with estrogen at lower doses (20 mcg and below) may reduce these side effects, and improve the effects on heart and circulation. Such preparations, however, may also increase spotting and break-through bleeding, depending on the progestin used.
Progesterone (Progestin)
When used in contraception, progesterone is referred to by one of several names:
-
Progesterone is actually the name for the natural hormone
-
Progestogen is a synthetic form
-
Progestin is the term for any substance, natural or synthetic, that causes progesterone effects. It is used as the general term in this report.
Effects on Reproduction. Progestins may be used alone or with estrogen in oral contraceptives. In addition, certain specific progestins are used in other kinds of contraceptives, such as levonorgestrel in implant systems and depo-medroxyprogesterone acetate in the injected Depo-Provera.
Progesterone can prevent pregnancy by itself in a number of ways:
- It blocks luteinizing hormone (LH), one of the reproductive hormones important in ovulation.
- It maintains a powerful barrier against the entry of sperm into the uterus by keeping the cervical mucus thick and sticky.
- It reduces the motility in the fallopian tubes, thereby inhibiting sperm transport.
- It changes the lining of the uterus and makes it more difficult for the fertilized egg to implant.
Progestins used in contraceptives are referred to as:
- Second generation (levonorgestrel, norethisterone).
- Third generation (desogestrel, gestodene, norgestimate, drospirenone). The third generation progestins tend to have fewer male-like side effects. Some studies suggest, however, they may pose a higher risk for blood clots than the older progestin, although the risk is still small. They possibly may have a better effect on cholesterol levels than earlier progestins, but this does not seem to translate into any particular heart benefits.
Side Effects of Progestins. Side effects of progestin occur in both the combination oral contraceptives and any contraceptive that only uses progestin, although they may be less or more severe depending on the form and dosage of the contraceptive. Side effects may include:
- Changes in uterine bleeding such as higher amounts during periods, spotting and bleeding between periods (called break-through bleeding), or absence of periods. Patients should check with the doctor if any of these occur.
- Unexpected flow of breast milk
- Abdominal pain or cramps
- Diarrhea
- Fatigue, unusual tiredness, weakness
- Hot flashes
- Decreased sex drive
- Nausea
- Trouble sleeping
- Acne or skin rash (low-dose OCs may improve acne)
- Depression, irritability, or other mood changes
- Swelling in the face, ankles, or feet
- Weight gain
Newer formulations of combination pills that use low-dose estrogen and newer progestins may reduce and avoid many of these side effects. Progestins used in non-oral contraceptives, such as the LNG-IUS IUD, may not pose as high a risk for these side effects. If side effects persist or are severe, a woman should always talk to her doctor. Many women do not experience these side effects, or if they do, their bodies eventually adjust.
|
GnRH Agonists
Gonadotropin releasing hormone (GnRH) agonists are sometimes used to treat menorrhagia. GnRH agonists block the release of the reproductive hormones LH (luteinizing hormone) and FSH (follicular-stimulating hormone). As a result, the ovaries stop ovulating and no longer produce estrogen. GnRH agonists include goserelin (Zoladex), buserelin, a monthly injection of leuprolide (depot Lupron), and a nasal spray, Nafarelin (Synarel). Such drugs may be used alone or in preparation for procedures used to destroy the uterine lining. They are not generally suitable for long-term use.
Commonly reported side effects, which can be severe in some women, include menopausal-like symptoms. These symptoms include hot flashes, night sweats, changes in the vagina, weight change, and depression. The side effects vary in intensity depending on the GnRH agonist. They may be more intense with leuprolide and persist after the drug has been stopped.
The most important concern is possible osteoporosis from estrogen loss. Women ordinarily should not take these drugs for more than 6 months. Certain approaches may preserve enough estrogen to protect bones and still effectively relieve endometriosis symptoms:
- Add-back therapy, which provides doses of estrogen and progestin that are high enough to maintain bone density, but are too low to offset the beneficial effects of the GnRH agonist.
- Intermittent leuprolide, which uses repeated 6-month courses of GnRH agonists followed by an average of nine months of symptom control only.
- Taking GnRH agonists in very low doses is an alternate approach, but is still largely untested.
- Adding a bone-protective drug called a bisphosphonate (alendronate or etidronate) may be helpful.
- Other drugs are being tested in combination with a GnRH agonist to preserve bone. They include parathyroid hormone or selective estrogen-receptor modulators (SERMs).
GnRH treatments used alone do not prevent pregnancy. Furthermore, if a woman becomes pregnant during their use, there is some risk for birth defects. Women who are taking GnRH agonists should use non-hormonal birth control methods, such as the diaphragm, cervical cap, or condoms while on the treatments.
Danazol
Danazol (Danocrine) is a synthetic substance that resembles a male hormone. It suppresses estrogen, and therefore menstruation, and is used (sometimes in combination with an oral contraceptive), to help prevent heavy bleeding. It may also improve surgical success rates in women with menorrhagia when used before ablation or resection to destroy the uterine lining. It is not suitable for long-term use.
Adverse side effects include facial hair, deepening of the voice, weight gain, acne, and dandruff. It may also increase the risk for unhealthy cholesterol levels. Pregnant women or those trying to become pregnant should not take this drug because it may cause birth defects. [For more information on this drug, see In-Depth Report #74: Endometriosis or In-Depth Report #63: Uterine fibroids.]
Review Date: 06/11/2006
Reviewed By: Harvey Simon, M.D., Editor-in-Chief, Associate Professor of
Medicine, Harvard Medical School; Physician, Massachusetts General
Hospital
| |
.gif)
