Premarin Cream
Generic Name: conjugated estrogens
Dosage Form: Vaginal cream
NOTE: PATIENT INFORMATION
LEAFLET ATTACHED.
Rx
only
ESTROGENS INCREASE THE RISK OF ENDOMETRIAL CANCER
Close clinical surveillance of all women taking estrogens
is important. Adequate diagnostic measures, including endometrial sampling
when indicated, should be undertaken to rule out malignancy in all cases of
undiagnosed persistent or recurring abnormal vaginal bleeding. There is no
evidence that the use of “natural” estrogens results in a different
endometrial risk profile than synthetic estrogens of equivalent estrogen dose.
(See WARNINGS, Malignant neoplasms,
Endometrial cancer.)
CARDIOVASCULAR AND OTHER RISKS
Estrogens with or without progestins should not be used for
the prevention of cardiovascular disease or dementia. (See CLINICAL STUDIES and WARNINGS, Cardiovascular disorders and Dementia.)
The
estrogen-alone substudy of the Women's Health Initiative (WHI) reported
increased risks of stroke and deep vein thrombosis (DVT) in postmenopausal
women (50 to 79 years of age) during 6.8 years and 7.1 years, respectively,
of treatment with oral conjugated estrogens (CE 0.625 mg) per day relative
to placebo. (See CLINICAL
STUDIES and WARNINGS,
Cardiovascular disorders.)
The
estrogen-plus-progestin substudy of the WHI reported increased risks of myocardial
infarction, stroke, invasive breast cancer, pulmonary emboli, and deep vein
thrombosis in postmenopausal women (50 to 79 years of age) during 5.6 years
of treatment with oral conjugated estrogens (CE 0.625 mg) combined with
medroxyprogesterone acetate (MPA 2.5 mg) per day relative to placebo.
(See CLINICAL STUDIES and WARNINGS, Cardiovascular
disorders and Malignant
neoplasms, Breast cancer.)
The
Women's Health Initiative Memory Study (WHIMS), a substudy of WHI, reported
an increased risk of developing probable dementia in postmenopausal women
65 years of age or older during 5.2 years of treatment with oral CE 0.625
mg alone and during four years of treatment with CE 0.625 mg combined with
MPA 2.5 mg, relative to placebo. It is unknown whether this finding applies
to younger postmenopausal women. (See CLINICAL STUDIES and WARNINGS, Dementia and PRECAUTIONS, Geriatric Use.)
Other doses of conjugated estrogens and
medroxyprogesterone acetate, and other combinations and dosage forms of estrogens
and progestins, were not studied in the WHI clinical trials, and in the absence
of comparable data, these risks should be assumed to be similar. Because of
these risks, estrogens with or without progestins should be prescribed at
the lowest effective doses and for the shortest duration consistent with treatment
goals and risks for the individual woman.
DESCRIPTION
Each gram of Premarin® (conjugated estrogens)
Vaginal Cream contains 0.625 mg conjugated estrogens, USP in a nonliquefying
base containing cetyl esters wax, cetyl alcohol, white wax, glyceryl monostearate,
propylene glycol monostearate, methyl stearate, benzyl alcohol, sodium lauryl
sulfate, glycerin, and mineral oil. Premarin Vaginal Cream is applied intravaginally.
Premarin(conjugated estrogens) Vaginal Cream contains a mixture of conjugated estrogens
obtained exclusively from natural sources, occurring as the sodium salts of
water-soluble estrogen sulfates blended to represent the average composition
of material derived from pregnant mares' urine. It is a mixture of sodium
estrone sulfate and sodium equilin sulfate. It contains as concomitant components,
as sodium sulfate conjugates, 17 α-dihydroequilin, 17 α-estradiol,
and 17 β-dihydroequilin.
CLINICAL PHARMACOLOGY
Endogenous estrogens are largely responsible for the development
and maintenance of the female reproductive system and secondary sexual characteristics.
Although circulating estrogens exist in a dynamic equilibrium of metabolic
interconversions, estradiol is the principal intracellular human estrogen
and is substantially more potent than its metabolites, estrone and estriol,
at the receptor level.
The primary source of estrogen
in normally cycling adult women is the ovarian follicle, which secretes 70
to 500 mcg of estradiol daily, depending on the phase of the menstrual
cycle. After menopause, most endogenous estrogen is produced by conversion
of androstenedione, secreted by the adrenal cortex, to estrone by peripheral
tissues. Thus, estrone and the sulfate-conjugated form, estrone sulfate, are
the most abundant circulating estrogen in postmenopausal women.
Estrogens
act through binding to nuclear receptors in estrogen-responsive tissues. To
date, two estrogen receptors have been identified. These vary in proportion
from tissue to tissue.
Circulating estrogens modulate
the pituitary secretion of the gonadotropins, luteinizing hormone (LH) and
follicle stimulating hormone (FSH), through a negative feedback mechanism.
Estrogens act to reduce the elevated levels of these gonadotropins seen in
postmenopausal women.
Pharmacokinetics
A. Absorption
Conjugated estrogens are soluble in water and are well-absorbed
through the skin, mucous membranes, and the gastrointestinal tract after release
from the drug formulation.
B. Distribution
The distribution of exogenous estrogens is similar to that
of endogenous estrogens. Estrogens are widely distributed in the body and
are generally found in higher concentration in the sex hormone target organs.
Estrogens circulate in the blood largely bound to sex hormone-binding globulin
(SHBG) and albumin.
C. Metabolism
Exogenous estrogens are metabolized in the same manner as
endogenous estrogens. Circulating estrogens exist in a dynamic equilibrium
of metabolic interconversions. These transformations take place mainly in
the liver. Estradiol is converted reversibly to estrone, and both can be converted
to estriol, which is the major urinary metabolite. Estrogens also undergo
enterohepatic recirculation via sulfate and glucuronide conjugation in the
liver, biliary secretion of conjugates into the intestine, and hydrolysis
in the gut followed by reabsorption. In postmenopausal women a significant
proportion of the circulating estrogens exists as sulfate conjugates, especially
estrone sulfate, which serves as a circulating reservoir for the formation
of more active estrogens.
D. Excretion
Estradiol, estrone, and estriol are excreted in the urine,
along with glucuronide and sulfate conjugates.
E. Special Populations
No pharmacokinetic studies were conducted in special populations,
including patients with renal or hepatic impairment.
F. Drug Interactions
Data from a single-dose drug-drug interaction study involving
oral conjugated estrogens and medroxyprogesterone acetate indicate that the
pharmacokinetic dispositions of both drugs are not altered when the drugs
are coadministered. No other clinical drug-drug interaction studies have been
conducted with conjugated estrogens.
In vitro and in
vivo studies have shown that estrogens are metabolized partially by cytochrome
P450 3A4 (CYP3A4). Therefore, inducers or inhibitors of CYP3A4 may affect
estrogen drug metabolism. Inducers of CYP3A4, such as St. John's Wort
preparations (Hypericum perforatum), phenobarbital, carbamazepine, and rifampin,
may reduce plasma concentrations of estrogens, possibly resulting in a decrease
in therapeutic effects and/or changes in the uterine bleeding profile. Inhibitors
of CYP3A4, such as erythromycin, clarithromycin, ketoconazole, itraconazole,
ritonavir and grapefruit juice, may increase plasma concentrations of estrogens
and may result in side effects.
Clinical Studies
Women's Health Initiative Studies
The Women’s Health Initiative (WHI) enrolled approximately
27,000 predominantly healthy postmenopausal women in two substudies to assess
the risks and benefits of oral conjugated estrogens (CE 0.625 mg) alone or
in combination with medroxyprogesterone acetate (CE 0.625 mg/MPA 2.5 mg) compared
to placebo in the prevention of certain chronic diseases. The primary endpoint
was the incidence of coronary heart disease (CHD) (nonfatal myocardial infarction
(MI), silent MI and CHD death), with invasive breast cancer as the primary
adverse outcome. A “global index” included the earliest occurrence
of CHD, invasive breast cancer, stroke, pulmonary embolism (PE), endometrial
cancer (only in CE/MPA), colorectal cancer, hip fracture, or death due to
other causes. The study did not evaluate the effects of CE tablets or CE/MPA
on menopausal symptoms.
The estrogen-alone substudy
was stopped early because an increased risk of stroke was observed, and it
was deemed that no further information would be obtained regarding the risks
and benefits of estrogen alone in predetermined primary endpoints. Results
of the estrogen-alone substudy, which included 10,739 women (average age of
63 years, range 50 to 79; 75.3% White, 15.1% Black, 6.1% Hispanic, 3.6%
Other) after an average follow-up of 6.8 years, are presented in Table 1 below.
TABLE 1. RELATIVE AND ABSOLUTE RISK SEEN IN THE ESTROGEN-ALONE
SUBSTUDY OF WHI
| Event |
Relative
Risk CE vs. Placebo (95% nCIa) |
CE n
= 5,310 |
Placebo n
= 5,429 |
Absolute
Risk per 10,000 Women-years |
aNominal
confidence intervals unadjusted for multiple looks and multiple comparisons. bResults
are based on centrally adjudicated data for an average follow-up of 7.1 years. cResults
are based on an average follow-up of 6.8 years. dNot included
in Global Index. eAll deaths, except from breast or colorectal
cancer, definite/probable CHD, PE or cerebrovascular disease. fA
subset of the events was combined in a “global index,” defined
as the earliest occurrence of CHD events, invasive breast cancer, stroke,
pulmonary embolism, colorectal cancer, hip fracture, or death due to other
causes. |
| CHD eventsb
|
0.95 (0.79-1.16) |
53 |
56 |
| Non-fatal MIb
|
0.91
(0.73-1.14) |
40 |
43 |
| CHD deathb
|
1.01
(0.71-1.43) |
16 |
16 |
| Strokec
|
1.39 (1.10-1.77) |
44 |
32 |
| Deep vein thrombosisb,d
|
1.47 (1.06-2.06) |
23 |
15 |
| Pulmonary embolismb
|
1.37 (0.90-2.07) |
14 |
10 |
| Invasive breast
cancerb
|
0.80 (0.62-1.04) |
28 |
34 |
| Colorectal cancerc
|
1.08 (0.75-1.55) |
17 |
16 |
| Hip fracturec
|
0.61 (0.41-0.91) |
11 |
17 |
| Vertebral fracturesc,d
|
0.62 (0.42-0.93) |
11 |
17 |
| Total fracturesc,d
|
0.70 (0.63-0.79) |
139 |
195 |
| Death due to
other causesc,e
|
1.08 (0.88-1.32) |
53 |
50 |
| Overall mortalityc,d
|
1.04 (0.88-1.22) |
81 |
78 |
| Global Indexc,f
|
1.01 (0.91-1.12) |
192 |
190 |
For those outcomes included in the WHI “global index”
that reached statistical significance, the absolute excess risk per 10,000
women-years in the group treated with CE alone were 12 more strokes while
the absolute risk reduction per 10,000 women-years was six fewer hip fractures.
The absolute excess risk of events included in the “global index”
was a nonsignificant two events per 10,000 women-years. There was no difference
between the groups in terms of all-cause mortality. (See BOXED WARNINGS, WARNINGS, and PRECAUTIONS.)
Final
adjudicated results for CHD events from the estrogen-alone substudy, after
an average follow-up of 7.1 years, reported no overall difference for primary
CHD events (nonfatal MI, silent MI and CHD death) in women receiving CE alone
compared with placebo (see Table 1).
The
estrogen-plus-progestin substudy was also stopped early. According to the
predefined stopping rule, after an average follow-up of 5.2 years of treatment,
the increased risk of breast cancer and cardiovascular events exceeded the
specified benefits included in the “global index.” The absolute
excess risk of events included in the “global index” was 19
per 10,000 women-years (RR 1.15, 95% nCI 1.03-1.28).
For
those outcomes included in the WHI “global index” that reached
statistical significance after 5.6 years of follow-up, the absolute excess
risks per 10,000 women-years in the group treated with CE/MPA were six more
CHD events, seven more strokes, ten more PEs, and eight more invasive breast
cancers, while the absolute risk reductions per 10,000 women-years were seven
fewer colorectal cancers and five fewer hip fractures. (See BOXED WARNINGS, WARNINGS, and PRECAUTIONS.)
Results
of the estrogen-plus-progestin substudy, which included 16,608 women (average
age of 63 years, range 50 to 79; 83.9% White, 6.8% Black, 5.4% Hispanic,
3.9% Other) are presented in Table 2 below.
These results reflect centrally adjudicated data after an average follow-up
of 5.6 years.
TABLE 2. RELATIVE
AND ABSOLUTE RISK SEEN IN THE ESTROGEN-PLUS-PROGESTIN SUBSTUDY OF WHI AT AN
AVERAGE OF 5.6 YEARSa
| Event |
Relative
Risk CE/MPA vs. Placebo (95% nCIb) |
CE/MPA n
= 8,506 |
Placebo n
= 8,102 |
Absolute Risk per
10,000 Women-years |
aResults are based on centrally adjudicated
data. Mortality data was not part of the adjudicated data; however, data at
5.2 years of follow-up showed no difference between the groups in terms of
all-cause mortality (RR 0.98, 95% nCI 0.82-1.18). bNominal
confidence intervals unadjusted for multiple looks and multiple comparisons. cIncludes metastatic and non-metastatic breast cancer with
the exception of in situ breast cancer. |
| CHD events |
1.24 (1.00-1.54) |
39 |
33 |
| Non-fatal MI
|
1.28
(1.00-1.63) |
31 |
25 |
| CHD death
|
1.10
(0.70-1.75) |
8 |
8 |
| All strokes |
1.31 (1.02-1.68) |
31 |
24 |
| Ischemic
stroke |
1.44
(1.09-1.90) |
26 |
18 |
| Deep vein thrombosis |
1.95 (1.43-2.67) |
26 |
13 |
| Pulmonary embolism |
2.13 (1.45-3.11) |
18 |
8 |
| Invasive breast
cancerc
|
1.24 (1.01-1.54) |
41 |
33 |
| Invasive colorectal
cancer |
0.56 (0.38-0.81) |
9 |
16 |
| Endometrial
cancer |
0.81 (0.48-1.36) |
6 |
7 |
| Cervical cancer |
1.44 (0.47-4.42) |
2 |
1 |
| Hip fracture |
0.67 (0.47-0.96) |
11 |
16 |
| Vertebral fractures |
0.65 (0.46-0.92) |
11 |
17 |
| Lower arm/wrist
fractures |
0.71 (0.59-0.85) |
44 |
62 |
| Total fractures |
0.76 (0.69-0.83) |
152 |
199 |
Women's Health Initiative Memory Study
The estrogen-alone Women's Health Initiative Memory
Study (WHIMS), a substudy of WHI, enrolled 2,947 predominantly healthy postmenopausal
women 65 years of age and older (45%, age 65 to 69 years; 36%, 70
to 74 years; 19%, 75 years of age and older) to evaluate the effects of CE
0.625 mg daily on the incidence of probable dementia (primary outcome) compared
with placebo.
After an average follow-up of 5.2 years,
28 women in the estrogen-alone group (37 per 10,000 women-years) and
19 in the placebo group (25 per 10,000 women-years) were diagnosed with probable
dementia. The relative risk of probable dementia in the estrogen-alone group
was 1.49 (95% CI 0.83–2.66) compared to placebo. It is unknown whether
these findings apply to younger postmenopausal women. (See BOXED WARNINGS, WARNINGS, Dementia and PRECAUTIONS, Geriatric Use.)
The estrogen-plus-progestin WHIMS substudy
enrolled 4,532 predominantly healthy postmenopausal women 65 years of
age and older (47%, age 65 to 69 years; 35%, 70 to 74 years; 18%
were 75 years of age and older) to evaluate the effects of CE/MPA 0.625 mg
conjugated estrogens/2.5 mg medroxyprogesterone acetate daily on the incidence
of probable dementia (primary outcome) compared with placebo.
After
an average follow-up of four years, 40 women in the estrogen-plus-progestin
group (45 per 10,000 women-years) and 21 in the placebo group (22 per
10,000 women-years) were diagnosed with probable dementia. The relative risk
of probable dementia in the hormone therapy group was 2.05 (95% CI 1.21–3.48)
compared to placebo.
When data from the two populations
were pooled as planned in the WHIMS protocol, the reported overall relative
risk for probable dementia was 1.76 (95% CI 1.19-2.60). Differences between
groups became apparent in the first year of treatment. It is unknown whether
these findings apply to younger postmenopausal women. (See BOXED WARNINGS, WARNINGS, Dementia and PRECAUTIONS, Geriatric Use.)
INDICATIONS AND USAGE
Premarin (conjugated estrogens) Vaginal Cream is indicated
in the treatment of atrophic vaginitis and kraurosis vulvae.
CONTRAINDICATIONS
Premarin Vaginal Cream should not be used in women with any
of the following conditions:
- Undiagnosed abnormal genital bleeding.
- Known, suspected, or history of cancer of the breast.
- Known or suspected estrogen-dependent neoplasia.
- Active deep vein thrombosis, pulmonary embolism or a history of these
conditions.
- Active or recent (e.g., within past year) arterial thromboembolic disease
(e.g., stroke, myocardial infarction).
- Liver dysfunction or disease.
- Premarin Vaginal Cream should not be used in patients with known hypersensitivity
to its ingredients.
- Known or suspected pregnancy. There is no indication for Premarin Vaginal
Cream in pregnancy. There appears to be little or no increased risk of birth
defects in children born to women who have used estrogen and progestins from
oral contraceptives inadvertently during pregnancy. (See PRECAUTIONS.)
WARNINGS
See BOXED
WARNINGS.
Systemic absorption
may occur with the use of Premarin Vaginal Cream. The warnings, precautions,
and adverse reactions associated with oral Premarin treatment should be taken
into account.
1. Cardiovascular disorders
Estrogen-alone therapy has been associated with an increased
risk of stroke and deep vein thrombosis (DVT).
Estrogen-plus-progestin
therapy has been associated with an increased risk of myocardial infarction
as well as stroke, venous thrombosis and pulmonary embolism.
Should
any of these events occur or be suspected, estrogens should be discontinued
immediately.
Risk factors for arterial vascular disease
(e.g., hypertension, diabetes mellitus, tobacco use, hypercholesterolemia,
and obesity) and/or venous thromboembolism (e.g., personal history or family
history of VTE, obesity, and systemic lupus erythematosus) should be managed
appropriately.
a. Stroke
In the estrogen-alone substudy of the Women's Health
Initiative (WHI) study, a statistically significant increased risk of stroke
was reported in women receiving CE 0.625 mg daily compared to women receiving
placebo (44 vs. 32 per 10,000 women-years). The increase in risk was demonstrated
in year one and persisted. (See CLINICAL
STUDIES.)
In the estrogen-plus-progestin
substudy of the WHI, a statistically significant increased risk of stroke
was reported in women receiving CE/MPA 0.625 mg/2.5 mg daily compared to women
receiving placebo (31 vs. 24 per 10,000 women-years). The increase in risk
was demonstrated after the first year and persisted.
b. Coronary heart disease
In the estrogen-alone substudy of WHI, no overall effect
on coronary heart disease (CHD) events (defined as non-fatal MI, silent MI,
or death, due to CHD) was reported in women receiving estrogen alone compared
to placebo. (See CLINICAL
STUDIES.)
In the estrogen-plus-progestin
substudy of WHI, no statistically significant increase of CHD events was reported
in women receiving CE/MPA compared to women receiving placebo (39 vs. 33 per
10,000 women years). An increase in relative risk was demonstrated in year
one, and a trend toward decreasing relative risk was reported in years 2 through
5.
In postmenopausal women with documented heart disease
(n = 2,763, average age 66.7 years) a controlled clinical trial of secondary
prevention of cardiovascular disease (Heart and Estrogen/progestin Replacement
Study; HERS) treatment with CE/MPA 0.625 mg conjugated estrogens/2.5 mg
medroxyprogesterone acetate daily demonstrated no cardiovascular benefit.
During an average follow-up of 4.1 years, treatment with CE/MPA did not reduce
the overall rate of CHD events in postmenopausal women with established coronary
heart disease. There were more CHD events in the CE/MPA-treated group than
in the placebo group in year one, but not during the subsequent years. Two
thousand three hundred and twenty one women from the original HERS trial agreed
to participate in an open-label extension of HERS, HERS II. Average follow-up
in HERS II was an additional 2.7 years, for a total of 6.8 years overall.
Rates of CHD events were comparable among women in the CE/MPA group and the
placebo group in the HERS, the HERS II, and overall.
Large
doses of estrogen (5 mg conjugated estrogens per day), comparable to
those used to treat cancer of the prostate and breast, have been shown in
a large prospective clinical trial in men to increase the risks of nonfatal
myocardial infarction, pulmonary embolism, and thrombophlebitis.
c. Venous thromboembolism (VTE)
In the estrogen-alone substudy of WHI, the risk of VTE (DVT
and pulmonary embolism [PE]), was reported to be increased for women taking
conjugated estrogens (30 vs. 22 per 10,000 women-years), although only the
increased risk of DVT reached statistical significance (23 vs. 15 per 10,000
women years). The increase in VTE risk was demonstrated during the first two
years. (See CLINICAL STUDIES.)
In the estrogen-plus-progestin substudy
of WHI, a statistically significant 2-fold greater rate of VTE was reported
in women receiving CE/MPA compared to women receiving placebo (35 vs. 17 per
10,000 women-years). Statistically significant increases in risk for both
DVT (26 vs. 13 per 10,000 women-years) and PE (18 vs. 8 per 10,000 women years)
were also demonstrated. The increase in VTE risk was demonstrated during the
first year and persisted.
If feasible, estrogens should
be discontinued at least 4 to 6 weeks before surgery of the type associated
with an increased risk of thromboembolism, or during periods of prolonged
immobilization.
2. Malignant neoplasms
a. Endometrial cancer
The use of unopposed estrogens in women with intact uteri
has been associated with an increased risk of endometrial cancer. The reported
endometrial cancer risk among unopposed estrogen users is about 2- to 12-fold
greater than in non-users, and appears dependent on duration of treatment
and on estrogen dose. Most studies show no significant increased risk associated
with use of estrogens for less than one year. The greatest risk appears associated
with prolonged use, with increased risks of 15- to 24-fold for five to ten
years or more and this risk has been shown to persist for at least 8 to 15
years after estrogen therapy is discontinued.
Clinical
surveillance of all women taking estrogen/progestin combinations is important.
Adequate diagnostic measures, including endometrial sampling when indicated,
should be undertaken to rule out malignancy in all cases of undiagnosed persistent
or recurring abnormal vaginal bleeding. There is no evidence that the use
of natural estrogens results in a different endometrial risk profile than
synthetic estrogens of equivalent estrogen dose. Adding a progestin to postmenopausal
estrogen therapy has been shown to reduce the risk of endometrial hyperplasia,
which may be a precursor to endometrial cancer.
b. Breast cancer
In some studies, the use of estrogens and progestins by
postmenopausal women has been reported to increase the risk of breast cancer.
The most important randomized clinical trial providing information about this
issue is the Women's Health Initiative (WHI) (see CLINICAL STUDIES). The results
from observational studies are generally consistent with those of the WHI
clinical trial.
Observational studies have also reported
an increased risk of breast cancer for estrogen-plus-progestin combination
therapy, and a smaller increased risk for estrogen-alone therapy, after several
years of use. For both findings, the excess risk increased with duration of
use, and appeared to return to baseline over about five years after stopping
treatment (only the observational studies have substantial data on risk after
stopping). In these studies, the risk of breast cancer was greater, and became
apparent earlier, with estrogen-plus-progestin combination therapy as compared
to estrogen-alone therapy. However, these studies have not found significant
variation in the risk of breast cancer among different estrogens or among
different estrogen-plus-progestin combinations, doses, or routes of administration.
In
the estrogen-alone substudy of WHI, after an average of 7.1 years of follow-up,
CE (0.625 mg daily) was not associated with an increased risk of invasive
breast cancer (RR 0.80, 95% nCI 0.62-1.04).
In the estrogen-plus-progestin
substudy, after a mean follow-up of 5.6 years, the WHI substudy reported an
increased risk of breast cancer. In this substudy, prior use of estrogen alone
or estrogen-plus-progestin combination hormone therapy was reported by 26%
of the women. The relative risk of invasive breast cancer was 1.24 (95%
nCI 1.01-1.54), and the absolute risk was 41 vs. 33 cases per 10,000 women-years,
for estrogen plus progestin compared with placebo, respectively. Among women
who reported prior use of hormone therapy, the relative risk of invasive breast
cancer was 1.86, and the absolute risk was 46 vs. 25 cases per 10,000 women-years,
for estrogen plus progestin compared with placebo. Among women who reported
no prior use of hormone therapy, the relative risk of invasive breast cancer
was 1.09, and the absolute risk was 40 vs. 36 cases per 10,000 women-years
for estrogen plus progestin compared with placebo. In the WHI trial, invasive
breast cancers were larger and diagnosed at a more advanced stage in the estrogen-plus-progestin
group compared with the placebo group. Metastatic disease was rare, with no
apparent difference between the two groups. Other prognostic factors, such
as histologic subtype, grade and hormone receptor status did not differ between
the groups.
The use of estrogen alone and estrogen
plus progestin has been reported to result in an increase in abnormal mammograms
requiring further evaluation.
All women should receive
yearly breast examinations by a healthcare provider and perform monthly breast
self-examinations. In addition, mammography examinations should be scheduled
based on patient age, risk factors, and prior mammogram results.
3. Dementia
In the estrogen-alone Women's Health Initiative Memory
Study (WHIMS), a substudy of WHI, a population of 2,947 hysterectomized women
aged 65 to 79 years was randomized to CE (0.625 mg daily) or placebo.
In the estrogen-plus-progestin WHIMS substudy, a population of 4,532 postmenopausal
women aged 65 to 79 years was randomized to CE/MPA (0.625 mg/2.5 mg daily)
or placebo.
In the estrogen-alone substudy, after
an average follow-up of 5.2 years, 28 women in the estrogen-alone group and
19 women in the placebo group were diagnosed with probable dementia. The relative
risk of probable dementia for CE alone vs. placebo was 1.49 (95% CI 0.83-2.66).
The absolute risk of probable dementia for CE alone vs. placebo was 37 vs.
25 cases per 10,000 women-years.
In the estrogen-plus-progestin
substudy, after an average follow-up of four years, 40 women in the estrogen-plus-progestin
group and 21 women in the placebo group were diagnosed with probable dementia.
The relative risk of probable dementia for estrogen plus progestin vs. placebo
was 2.05 (95% CI 1.21-3.48). The absolute risk of probable dementia
for CE/MPA vs. placebo was 45 vs. 22 cases per 10,000 women-years.
When
data from the two populations were pooled as planned in the WHIMS protocol,
the reported overall relative risk for probable dementia was 1.76 (95% CI
1.19-2.60). Since both substudies were conducted in women aged 65 to 79 years,
it is unknown whether these findings apply to younger postmenopausal women.
(See BOXED WARNINGS and PRECAUTIONS,
Geriatric Use.)
4. Gallbladder disease
A 2- to 4-fold increase in the risk of gallbladder disease
requiring surgery in postmenopausal women receiving postmenopausal estrogens
has been reported.
5. Hypercalcemia
Estrogen administration may lead to severe hypercalcemia
in patients with breast cancer and bone metastases. If hypercalcemia occurs,
use of the drug should be stopped and appropriate measures taken to reduce
the serum calcium level.
6. Visual abnormalities
Retinal vascular thrombosis has been reported in patients
receiving estrogens. Discontinue medication pending examination if there is
sudden partial or complete loss of vision, or a sudden onset of proptosis,
diplopia, or migraine. If examination reveals papilledema or retinal vascular
lesions, estrogens should be discontinued.
PRECAUTIONS
A. General
1. Addition of a progestin when a woman has not had a hysterectomy
Studies of the addition of a progestin for 10 or more days
of a cycle of estrogen administration or daily with estrogen in a continuous
regimen have reported a lowered incidence of endometrial hyperplasia than
would be induced by estrogen treatment alone. Endometrial hyperplasia may
be a precursor to endometrial cancer.
There are, however,
possible risks that may be associated with the use of progestins with estrogens
compared to estrogen-alone regimens. These include a possible increased risk
of breast cancer, adverse effects on lipoprotein metabolism (e.g., lowering
HDL, raising LDL) and impairment of glucose tolerance.
2. Elevated blood pressure
In a small number of case reports, substantial increases
in blood pressure have been attributed to idiosyncratic reactions to estrogens.
In a large, randomized, placebo-controlled clinical trial, a generalized effect
of estrogen therapy on blood pressure was not seen. Blood pressure should
be monitored at regular intervals with estrogen use.
3. Hypertriglyceridemia
In patients with pre-existing hypertriglyceridemia, estrogen
therapy may be associated with elevations of plasma triglycerides leading
to pancreatitis and other complications.
4. Impaired liver function and past history of cholestatic jaundice
Estrogens may be poorly metabolized in patients with impaired
liver function. For patients with a history of cholestatic jaundice associated
with past estrogen use or with pregnancy, caution should be exercised, and
in the case of recurrence, medication should be discontinued.
5. Hypothyroidism
Estrogen administration leads to increased thyroid-binding
globulin (TBG) levels. Patients with normal thyroid function can compensate
for the increased TBG by making more thyroid hormone, thus maintaining free
T4 and T3 serum concentrations in the normal range.
Patients dependent on thyroid hormone replacement therapy who are also receiving
estrogens may require increased doses of their thyroid replacement therapy.
These patients should have their thyroid function monitored in order to maintain
their free thyroid hormone levels in an acceptable range.
6. Fluid retention
Because estrogens may cause some degree of fluid retention,
patients with conditions that might be influenced by this factor, such as
cardiac or renal dysfunction, warrant careful observation when estrogens are
prescribed.
7. Hypocalcemia
Estrogens should be used with caution in individuals with
severe hypocalcemia.
8. Ovarian cancer
The estrogen-plus-progestin substudy of WHI reported that
after an average follow-up of 5.6 years, the relative risk for ovarian
cancer for estrogen plus progestin vs. placebo was 1.58 (95% nCI 0.77– 3.24), but was not statistically significant. The absolute risk for
estrogen plus progestin vs. placebo was 4.2 vs. 2.7 cases per 10,000 women-years.
In some epidemiologic studies, the use of estrogen-only products, in particular
for 10 or more years, has been associated with an increased risk of ovarian
cancer. Other epidemiologic studies have not found these associations.
9. Exacerbation of endometriosis
Endometriosis may be exacerbated with administration of estrogen
therapy.
Malignant transformation of residual endometrial
implants have been reported in women treated post-hysterectomy with estrogen-alone
therapy. For patients known to have residual endometriosis post-hysterectomy,
the addition of progestin should be considered.
10. Exacerbation of other conditions
Estrogen therapy may cause an exacerbation of asthma, diabetes
mellitus, epilepsy, migraine, porphyria, systemic lupus erythematosus, and
hepatic hemangiomas and should be used with caution in women with these conditions.
11. Barrier contraceptives
Premarin Vaginal Cream exposure has been reported to weaken
latex condoms. The potential for Premarin Vaginal Cream to weaken and contribute
to the failure of condoms, diaphragms, or cervical caps made of latex or rubber
should be considered.
B. Patient Information
Physicians are advised to discuss the contents of the PATIENT INFORMATION leaflet
with patients for whom they prescribe Premarin Vaginal Cream.
C. Laboratory Tests
Estrogen administration should be guided by clinical response
at the lowest dose for the treatment of postmenopausal vulvar and vaginal
atrophy.
D. Drug/Laboratory Test Interactions
- Accelerated prothrombin time, partial thromboplastin time, and platelet
aggregation time; increased platelet count; increased factors II, VII antigen,
VIII antigen, VIII coagulant activity, IX, X, XII, VII-X complex, II-VII-X
complex, and beta-thromboglobulin; decreased levels of antifactor Xa and antithrombin
III, decreased antithrombin III activity; increased levels of fibrinogen and
fibrinogen activity; increased plasminogen antigen and activity.
- Increased thyroid-binding globulin (TBG) leading to increased circulating
total thyroid hormone, as measured by protein-bound iodine (PBI), T4 levels
(by column or by radioimmunoassay) or T3 levels by radioimmunoassay.
T3 resin uptake is decreased, reflecting the elevated TBG. Free
T4 and free T3 concentrations are unaltered. Patients
on thyroid replacement therapy may require higher doses of thyroid hormone.
- Other binding proteins may be elevated in serum, i.e., corticosteroid
binding globulin (CBG), sex hormone-binding globulin (SHBG), leading to increased
total circulating corticosteroids and sex steroids, respectively. Free hormone
concentrations may be decreased. Other plasma proteins may be increased (angiotensinogen/renin
substrate, alpha-1-antitrypsin, ceruloplasmin).
- Increased plasma HDL and HDL2 cholesterol subfraction concentrations,
reduced LDL cholesterol concentration, increased triglyceride levels.
- Impaired glucose tolerance.
- Reduced response to metyrapone test.
E. Carcinogenesis, Mutagenesis, Impairment of Fertility
(See BOXED
WARNINGS, WARNINGS, and PRECAUTIONS.)
Long-term continuous administration of
natural and synthetic estrogens in certain animal species increases the frequency
of carcinomas of the breast, uterus, cervix, vagina, testis, and liver.
F. Pregnancy
Premarin Vaginal Cream should not be used during pregnancy.
(See CONTRAINDICATIONS.)
G. Nursing Mothers
Estrogen administration to nursing mothers has been shown
to decrease the quantity and quality of breast milk. Detectable amounts of
estrogens have been identified in the milk of mothers receiving the drug.
Caution should be exercised when Premarin Vaginal Cream is administered to
a nursing woman.
H. Pediatric Use
Estrogen therapy has been used for the induction of puberty
in adolescents with some forms of pubertal delay. Safety and effectiveness
in pediatric patients have not otherwise been established.
Large
and repeated doses of estrogen over an extended time period have been shown
to accelerate epiphyseal closure, which could result in short adult stature
if treatment is initiated before the completion of physiologic puberty in
normally developing children. If estrogen is administered to patients whose
bone growth is not complete, periodic monitoring of bone maturation and effects
on epiphyseal centers is recommended during estrogen administration.
Estrogen
treatment of prepubertal girls also induces premature breast development and
vaginal cornification, and may induce vaginal bleeding. In boys, estrogen
treatment may modify the normal pubertal process and induce gynecomastia.
(See INDICATIONS AND USAGE and DOSAGE AND
ADMINISTRATION.)
I. Geriatric Use
Of the total number of subjects in the estrogen-alone substudy
of the Women's Health Initiative (WHI) study, 46% (n=4,943) were 65 years
and over, while 7.1% (n=767) were 75 years and over. There was a higher relative
risk (CE vs. placebo) of stroke in women less than 75 years of age compared
to women 75 years and over.
In the estrogen-alone Women's
Health Initiative Memory Study (WHIMS), a substudy of WHI, a population of
2,947 hysterectomized women, aged 65 to 79 years, was randomized to CE (0.625 mg
daily) or placebo. After an average follow-up of 5.2 years, the relative risk
(CE vs. placebo) of probable dementia was 1.49 (95% CI 0.83-2.66). The absolute
risk of developing probable dementia with estrogen alone was 37 vs. 25 cases
per 10,000 women-years with placebo.
Of the total number
of subjects in the estrogen-plus-progestin substudy of the Women's Health
Initiative study, 44% (n = 7,320) were 65–74 years of age, while 6.6%
(n = 1,095) were 75 years and over. There was a higher relative
risk (CE/MPA vs. placebo) of non-fatal stroke and invasive breast cancer in
women 75 and over compared to women less than 75 years of age. In women greater
than 75, the increased risk of non-fatal stroke and invasive breast cancer
observed in the estrogen-plus-progestin combination group compared to the
placebo group was 75 vs. 24 per 10,000 women-years and 52 vs. 12 per 10,000
women-years, respectively.
In the estrogen-plus-progestin
WHIMS substudy, a population of 4,532 postmenopausal women, aged 65 to 79
years, was randomized to CE/MPA (0.625 mg/2.5 mg daily) or placebo. In the
estrogen-plus-progestin group, after an average follow-up of four years, the
relative risk (CE/MPA vs. placebo) of probable dementia was 2.05 (95% CI 1.21-3.48).
The absolute risk of developing probable dementia with CE/MPA was 45 vs. 22
cases per 10,000 women-years with placebo.
Seventy-nine
percent of the cases of probable dementia occurred in women that were older
than 70 for the CE group, and 82 percent of the cases of probable dementia
occurred in women who were older than 70 in the CE/MPA group. The most common
classification of probable dementia in both the treatment groups and placebo
groups was Alzheimer’s disease.
When data from
the two populations were pooled as planned in the WHIMS protocol, the reported
overall relative risk for probable dementia was 1.76 (95% CI 1.19-2.60). Since
both substudies were conducted in women aged 65 to 79 years, it is unknown
whether these findings apply to younger postmenopausal women. (See BOXED WARNINGS and WARNINGS, Dementia.)
There
have not been sufficient numbers of geriatric patients involved in studies
utilizing Premarin Vaginal Cream to determine whether those over 65 years
of age differ from younger subjects in their response to Premarin Vaginal
Cream.
Adverse Reactions
See BOXED
WARNINGS, WARNINGS, and PRECAUTIONS.
Systemic absorption may occur with the
use of Premarin Vaginal Cream. Warnings, precautions, and adverse reactions
associated with oral Premarin treatment should be taken into account.
The
following additional adverse reactions have been reported with estrogen and/or
progestin therapy:
-
Genitourinary system: Breakthrough
bleeding, spotting, changes in vaginal bleeding pattern and abnormal withdrawal
bleeding or flow; dysmenorrhea; increase in size of uterine leiomyomata; vaginitis,
including vaginal candidiasis; change in cervical erosion and in degree of
cervical secretion; cystitis-like syndrome; application site reactions of
vulvovaginal discomfort including burning and irritation; genital pruritus;
ovarian cancer; endometrial hyperplasia; endometrial cancer; precocious puberty.
-
Breasts: Tenderness, pain, enlargement,
secretion; breast cancer; fibrocystic breast changes.
-
Cardiovascular: Deep and superficial
venous thrombosis, pulmonary embolism, thrombophlebitis, myocardial infarction,
stroke; increase in blood pressure.
-
Gastrointestinal: Nausea, vomiting,
abdominal cramps, bloating; cholestatic jaundice; pancreatitis; increased
incidence of gallbladder disease; enlargement of hepatic hemangiomas.
-
Skin: Chloasma or melasma which
may persist when drug is discontinued; erythema multiforme; erythema nodosum;
hemorrhagic eruption; loss of scalp hair; hirsutism; pruritis; rash.
-
Eyes: Retinal vascular thrombosis;
intolerance to contact lenses.
-
Central Nervous System: Headache;
migraine; dizziness; nervousness; mood disturbances; irritability; mental
depression; chorea; exacerbation of epilepsy; dementia.
-
Miscellaneous: Increase or decrease
in weight; reduced carbohydrate tolerance; glucose intolerance; aggravation
of porphyria; edema; changes in libido; urticaria, angioedema, anaphylactoid/anaphylactic
reactions; hypocalcemia; exacerbation of asthma; increased triglycerides;
arthralgias; leg cramps.
OVERDOSAGE
Serious ill effects have not been reported following acute
ingestion of large doses of estrogen/progestin containing drug products by
young children. Overdosage of estrogens may cause nausea and vomiting, and
withdrawal bleeding may occur in females.
DOSAGE AND ADMINISTRATION
Use of Premarin Vaginal Cream, alone or in combination with
a progestin, should be limited to the shortest duration consistent with treatment
goals and risks for the individual woman. Patients should be reevaluated periodically
as clinically appropriate (e.g., at 3-month to 6-month intervals) to determine
if treatment is still necessary (See BOXED
WARNINGS and WARNINGS). For women who have a uterus, adequate diagnostic measures, such
as endometrial sampling, when indicated, should be undertaken to rule out
malignancy in cases of undiagnosed persistent or recurring abnormal vaginal
bleeding.
Given cyclically
for short-term use only:
For treatment of
atrophic vaginitis, or kraurosis vulvae. The lowest dose that will control
symptoms should be chosen and medication should be discontinued as promptly
as possible. Administration should be cyclic (e.g., three weeks on and one
week off).
Usual Dosage Range:
½ to 2 g daily,
intravaginally, depending on the severity of the condition.
Instructions For Use Of Gentle Measure™ Applicator
- Remove cap from tube.
- Screw nozzle end of applicator onto tube.
-
Gently squeeze tube from the bottom to force sufficient cream into the barrel
to provide the prescribed dose. Use the marked stopping points on the applicator
as a guideline to measure the correct dose.
- Unscrew applicator from tube.
- Lie on back with knees drawn up. To deliver medication, gently insert
applicator deeply into vagina and press plunger downward to its original position.
To Cleanse: Pull plunger to remove it from barrel. Wash
w
Recent Drug Updates at Web Drug List
Blephamide
Cartrol
DermiCort Topical
DiaBeta
Empirin with Codeine
Feverfew
Guanadrel
MZM
Nitrostat oral/buccal/sublingual/spray
Paricalcitol
|