Menstrual Disorders - Medications

The Mirena is the current standard brand. FibroPlant is a unique "frameless" LNG-IUS device is very small and secretes a very low dose of progestin. It appears to have very few hormonal effects, although comparison studies are needed to prove any significant advantages over the Mirena. The LNG-IUS releases progestin for up to seven years. Progestin released by an IUD mainly effects the uterus and cervix and so it causes fewer widespread side effects than the progestin pills do. (It should be noted that the other major IUD--the Copper T--may increase bleeding.)

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Irregular break-through bleeding can occur for the first six months, but afterward 80% to 90% reduction in blood loss has been reported. It is well tolerated. 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. Of some concern was a 2002 study that found changes in the arteries of long-time users suggesting a risk for future heart disease. More research on this finding is warranted.

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 two or three months of use of oral contraceptives, side effects from estrogen in the combined pill includes:

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. A reassuring 2002 study supported an earlier major study, with both finding no evidence that OC use increases the risk for breast cancer, even in women who have taken them for 15 years or more or had taken them at young ages. Still, more research is needed to verify these findings, given previous reports of a slightly higher risk.
Estrogen has mixed effects on heart. It appears to improve cholesterol and other lipid levels. However, it also increases blood clotting and may increase the risk for stroke in certain women. 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 agent, 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 (e.g. levonorgestrel, norethisterone).
Third generation (e.g. 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 the following:

Changes in uterine bleeding. Such as higher amounts during periods, spotting and bleeding between periods (called break-through bleeding), or absence of periods. Be sure to check with the physician if any of these occur.
Unexpected flow of breast milk. (Check with the physician if this occurs to be sure other abnormalities are not causing it.)
Abdominal pain or cramps.
Diarrhea.
Fatigue, unusual tiredness, weakness.
Hot flashes.
Decreased sex drive.
Nausea.
Trouble sleeping.
Acne or skin rash. (Low-dose OCs actually improve acne. Only Ortho Tri-Cyclen is approved for this.)
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 even avoid many of these side effects. Progestins used in non-oral contraceptives, such as the LNG-IUS IUD, also 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 physician. Many women do not experience these side effects, or if they do, their bodies eventually adjust.