GENERIC NAME: esterified
estrogens
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BRAND NAME: Estratan; Menest
DRUG CLASS AND MECHANISM: Esterified estrogens are a
mixture of several estrogens, a type of female hormone.
Estrogens cause growth and development of female sex
organs and the maintenance of sex characteristics, including
growth of underarm and pubic hair and shaping of body
contours and skeleton. Estrogens also increase secretions
from the cervix and growth of the inner lining of the
uterus (endometrium). Estrogens reduce LDL - cholesterol
("bad" cholesterol) and increase HDL - cholesterol
("good" cholesterol) in the blood. Estrogens,
when taken alone or in combination with a progestin
(another type of female hormone), have been shown to
reduce the risk of heart attack (myocardial infarction)
and stroke by 40-50%. In addition, their bone-promoting
effects reduce the risk for hip fracture from osteoporosis
(a bone disease that occurs primarily in women after
menopause when the body stops producing its own estrogens)
by 25%.
PRESCRIPTION: yes
GENERIC AVAILABLE: yes
PREPARATIONS: Tablets: 0.3mg, 0.625mg, 1.25mg, 2.5mg.
STORAGE: Tablets should be stored between 2? (36°F)
and 30°C (86°F).
PRESCRIBED FOR: Esterified estrogens are prescribed
for the treatment of the common symptoms associated
with menopause (for, example, hot flashes and vaginal
dryness), dysfunctional (excessive and painful) uterine
bleeding, and prostate cancer, as well as for the prevention
of bone fractures associated with osteoporosis, heart
attacks, and strokes.
DOSING: Esterified estrogens are generally prescribed
once daily.
DRUG INTERACTIONS:
Cyclosporine levels: Estrogens can inhibit the metabolism
(destruction) of cyclosporine, resulting in increased
cyclosporine blood levels. Such increased blood levels
can result in kidney and/or liver damage. If the combination
of estrogens and cyclosporine cannot be avoided, cyclosporine
concentrations in the blood can be monitored, and the
dose of cyclosporine can be adjusted to assure that
its blood levels are not elevated.
Liver disease: Estrogens appear to increase the risk
of liver disease in patients receiving dantrolene through
an unknown mechanism. Women over 35 years of age and
those with a history of liver disease are especially
at risk.
Reduced effectiveness of anticoagulants: Estrogens
increase the liver's ability to manufacture chemicals
that are required in order for blood to clot. Therefore,
patients receiving warfarin (Coumadin), which anticoagulates
("thins" the blood) by inhibiting the manufacture
of the chemicals required for clotting, need to have
the ability of their blood to clot monitored if an estrogen
is added. If blood clots too easily, the dose of warfarin
may need to be increased.
Reduced effectiveness: Rifampin, barbiturates, carbamazepine
(Tegretol), griseofulvin, phenytoin (Dilantin) and primidone,
can increase the elimination of estrogen by enhancing
the liver's ability to metabolize (destroy) it. Use
of these drugs may result in a reduction of the beneficial
effects of estrogens.
PREGNANCY: Estrogens should not be used during pregnancy
because of an increased risk of fetal abnormalities.
NURSING MOTHERS: Estrogens are secreted in milk and
cause unpredictable effects in the infant. Therefore,
they generally should not be used during breast-feeding.
SIDE EFFECTS: Among the most common endocrine side
are breakthrough bleeding or spotting, loss of periods,
or excessively prolonged periods, breast pain, breast
enlargement, and changes in sexuality (increase or decrease
in libido). Estrogens also may cause gallstones, hepatitis,
migraine headaches, and fluid retention (swelling of
the lower legs). Melasma (tan or brown patches) may
develop on the forehead, cheeks, or temples. These may
persist even after the estrogen is stopped. Estrogens
may cause an increase in the curvature of the cornea,
and, therefore, patients with contact lenses may develop
intolerance to their lenses.
Blood clots: Blood clots are occasional but serious
side effects of estrogen therapy and are dose-related,
that is, they occur more frequently with higher doses.
Cigarette smokers are at a higher risk than non-smokers.
Therefore, patients requiring estrogen therapy are strongly
encouraged to quit smoking.
Uterine cancer: Estrogens can promote a build-up of
the lining of the uterus or endometrium (endometrial
hyperplasia) and increase the risk of endometrial cancer.
At diagnosis, endometrial cancers in estrogen users
are generally of an earlier stage and a lesser degree
of malignancy than in non-users. Survival, therefore,
is better. The addition of a progestin to estrogen therapy
prevents endometrial cancer from developing.
Breast cancer: Conflicting data exists on the association
between estrogen therapy and breast cancer. There may
be a small increase in risk. It is not clear if the
addition of a progestin during estrogen therapy reduces
the risk of breast cancer (as it does for uterine cancer).
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