There have been many changes in the way we prescribe estrogens and progestins. These methods are referred to by doctors as treatment regimens or treatment protocols. They range from taking the hormones alone to taking them in various combinations with another hormone; from taking them continuously to receiving treatment in cycles that involve time on and off the medication. Learning about the various regimens and why and how we select them can help you understand why you may be taking hormones every day, whereas your best friend takes them cyclically.
Estrogen used alone, either cyclically or continuously, has been associated with an increase in the risk of uterine cancer. For this reason, we add progesterone or progestin. (The progestin inhibits the growth stimulation of estrogen.) The combination of estrogen and progestin, taken cyclically, is the most popular method of HRT today.
The cyclic treatment most frequently prescribed works in accord with the calendar month. You take estrogen from the first through the twenty-fifth day of the cycle, adding progestin for the last twelve or thirteen days of the estrogen therapy, and then stop both medications for the final days of the month. Withdrawal bleeding may occur at the end of the month during the pill-free days.
There are three cyclic methods popularly in use in the United States today:
– You take estrogen tablets on days one to twenty-five of the month and add progestin for approximately twelve days (days fourteen to twenty-five). ,
– You use the estrogen patch, changing it twice weekly for twenty-five days and take oral progestin on days fourteen to twenty-five.
– You take one of the other estrogens and progestins in equivalent doses and cycle twenty-one days on and seven days off therapy.
These methods have one thing in common: About two-thirds of those women who have their uterus intact will experience a period during the treatment-free days. The amount of bleeding usually lessens over time and, after several years, may disappear altogether.
Continuous therapy involves the uninterrupted use of estrogen. Recent prescribing trends have moved away from the interrupted, or cycled, use of estrogen, which actually rests on little scientific foundation.
Continuous estrogen with intermittent progestin has become the most popular U.S. method of continuous therapy. It works this way: You take estrogen continuously, either as a daily tablet or as a skin patch changed twice each week. You take progestin on the first twelve days of the calendar month.
More than two-thirds of women with an intact uterus will, on this regimen, experience bleeding. Bleeding, however, should occur only after the twelfth day when the progestin is stopped and last until around the sixteenth day. If bleeding occurs before the ninth of the month, it may suggest that the dose of the progestin is too low and should be adjusted. Bleeding starting after the sixteenth day should be considered irregular and reported to your physician.
Combined Continuous Therapy
Combined continuous therapy is a more innovative method of hormone replacement. This therapy involves daily doses of estrogen combined with low daily doses of progestin. The combined continuous method attempts to avoid that most unpopular side effect of HRT, withdrawal bleeding, that usually occurs with cyclic therapy. Variable results of this therapy have been reported in recent medical literature.
Endometrial sampling (biopsy) is often required, which generally shows a mixed pattern of estrogen and progestin in the uterine lining. Most women do not like the irregular bleeding and stop taking therapy. Those who continue usually find that they stop bleeding after approximately six months.
Is it worth it? Further research is necessary in order to answer this question. It seems likely that this form of combined continuous therapy may become very popular in the future. The main hesitation in prescribing it now is the risk of giving the body too much progestin, with a possible risk of heart disease or breast disease as a result.
Continuous Progestin Therapy
Progestin only, taken continuously, is a form of therapy for women who cannot take estrogen because they have had breast or uterine cancer, or because they have severe fibrocystic breast disease. Women take it either daily in pill form or in monthly intramuscular shots.
Progestins help to prevent osteoporosis. Their protection of bone, however, is not as good as that of estrogen. The major disadvantage of progestin-only therapy is that it may increase the risk of heart disease.