
GENERIC NAME: conjugated estrogens vaginal cream
BRAND NAME: Premarin Vaginal Cream
DRUG CLASS AND MECHANISM: Conjugated estrogens are a
mixture of estrogen-related chemicals including estrone, equilin, 17
alpha-dihydroequilin,
and others. They are derived from the urine of pregnant horses, and
the exact composition of the estrogenic mixture is
uncertain. The vaginal cream is used for treating the uncomfortable
vaginal symptoms that may occur after menopause. Both oral and
vaginal estrogens reverse postmenopausal atrophy of the vaginal
lining, thickening the lining and increasing its secretions. Most
individuals taking estrogens orally do not need additional vaginal
estrogens.
Conjugated estrogens were first approved by the FDA in 1938.
GENERIC AVAILABLE: no
PRESCRIPTION: yes
PREPARATIONS: 0.625mg per application with accompanying
applicator, 42.5gm tube.
STORAGE: The cream should be stored at room temperature,
15-30°C (59-86°F).
PRESCRIBED FOR: Premarin vaginal cream is used for the
relief of vaginal symptoms in post-menopausal women who have
developed
uncomfortable dryness of the vagina and/or vulvae.
DOSING: Vaginal products work best if used at bedtime. The
hands should first be washed and the applicator filled with cream
from the tube. Lying on the back with the knees bent, individuals
should insert the applicator into the vagina and push the
applicator's plunger to deliver the cream. The applicator and
plunger then should be washed with warm, soapy water and rinsed with
plain water. The hands should be washed before and after use. A
small amount of the cream also can be applied to the outer skin folds
or "lips" of the vagina (vulvae) to relieve dryness or irritation.
DRUG INTERACTIONS: Estrogens can inhibit the elimination
of
cyclosporine from the body, resulting in increased cyclosporine
levels in the blood. These increased levels can result in kidney
and/or liver damage. If the
combination of cyclosporine and estrogens cannot be avoided,
cyclosporine concentrations can be measured in the blood, and the
dose of cyclosporine can be adjusted to assure that blood levels are
not elevated.
Estrogens appear to increase the risk of liver disease in patients
receiving dantrolene. The reason is not known. Women over 35 years
of
age and those who already have liver disease are especially at risk.
Estrogens increase the liver's ability to manufacture clotting
factors.
Because of this, patients receiving
warfarin (Coumadin)--which has its beneficial effects by reducing
clotting factors--need to be monitored for loss of anticoagulant
(blood
thinning) effect if an estrogen is begun.
Rifampin, barbiturates, carbamazepine (Tegretol), griseofulvin,
phenytoin
(Dilantin) and primidone (Mysoline), all can increase the elimination
of estrogen by
enhancing the liver's ability to metabolize it. Use of these drugs
may result
in reduction of the beneficial effects of estrogens.
PREGNANCY: Estrogens should be avoided during pregnancy
since they increase the risk of fetal abnormalities.
NURSING MOTHERS: Estrogens are secreted in milk and cause
unpredictable effects in the infant. In general, they should not be
used by women who are breast-feeding.
SIDE EFFECTS: Among the most common endocrine side effects
are
breakthrough vaginal bleeding or spotting, loss
of periods or excessively prolonged periods, breast pain or enlargement, and changes in
sexuality (increases or decreases in libido). Estrogens cause
gallstones, and the gallstones may result in abdominal pain and
require surgery. Rarely, estrogens may cause hepatitis.
Migraine headaches have been associated with estrogen therapy.
Estrogens
can cause retention of water (edema). Melasma--tan or brown patches--
may
develop on the forehead, cheeks, or temples. These may persist even
after
the estrogen is stopped. Conjugated estrogens may increase the
curvature of the cornea, and patients with contact lenses may develop
intolerance to their lenses.
Blood clots are an occasional, serious side effect of estrogen
therapy
and are dose-related. (The higher the dose of estrogen, the greater
the risk of blood clots.) Cigarette smokers are at a higher risk than
non-smokers for blood clots, and patients
requiring estrogens should be encouraged to quit smoking.
Estrogens can promote thickening of the lining of the uterus
(endometrial
hyperplasia) and increase the risk of uterine cancer. At diagnosis,
endometrial cancers in recipients of estrogens are generally at an
earlier
stage and are less aggressive when they are discovered. Survival
from endometrial cancer also is better in women taking estrogens than
in those not taking estrogens. The addition of a progestin to
estrogen therapy offsets the risk of endometrial cancer.
Conflicting data exists on the association between estrogens and
breast
cancer. There may be a small increase in risk. The effect of
concomitant
progestin therapy on the risk of estrogen-induced breast cancer is
unclear.
Conjugated estrogens are well-absorbed from the vagina and into
the blood. The amount absorbed depends on the frequency of use and
the amount used. Thus, more frequent use or larger amounts of vaginal
estrogens can have effects throughout the body (see conjugated
estrogens, Premarin).
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From the Doctors at MedicineNet.com  |
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Back to Medications IndexLast Editorial Review: 3/26/2000 9:27:00 PM