WARNINGS
Cigarette
smoking increases the risk of serious cardiovascular side effects
from oral contraceptive use. This risk increases with age and with
heavy smoking (15 or more cigarettes per day) and is quite marked
in women over 35 years of age. Women who use oral contraceptives
should be strongly advised not to smoke.
Drospirenone
YASMIN contains 3 mg of the progestin drospirenone
that has antimineralocorticoid activity, including the potential
for hyperkalemia in high-risk patients, comparable to a 25 mg dose
of spironolactone. YASMIN should not be used in patients with conditions
that predispose to hyperkalemia (i.e. renal insufficiency, hepatic
dysfunction and adrenal insufficiency). Women receiving daily, long-term
treatment for chronic conditions or diseases with medications that
may increase serum potassium, should have their serum potassium
level checked during the first treatment cycle. Drugs that may increase
serum potassium include ACE inhibitors, angiotensin–II receptor
antagonists, potassium-sparing diuretics, heparin, aldosterone antagonists,
and NSAIDs.
General
The use of oral contraceptives is associated with
increased risks of several serious conditions including myocardial
infarction, thromboembolism, stroke, hepatic neoplasia, gallbladder
disease, and hypertension, although the risk of serious morbidity
or mortality is very small in healthy women without underlying risk
factors. The risk of morbidity and mortality increases significantly
in the presence of other underlying risk factors such as hypertension,
hyperlipidemias, obesity and diabetes.
Practitioners prescribing oral contraceptives should
be familiar with the following information relating to these risks.
The information contained in this package insert is
based principally on studies carried out in patients who used oral
contraceptives with higher formulations of estrogens and progestogens
than those in common use today. The effect of long-term use of the
oral contraceptives with lower formulations of both estrogens and
progestogens remains to be determined.
Throughout this labeling, epidemiologic studies reported
are of two types: retrospective or case control studies and prospective
or cohort studies. Case control studies provide a measure of the
relative risk of a disease, namely, a ratio of the incidence of
a disease among oral contraceptive users to that among nonusers.
The relative risk does not provide information on the actual clinical
occurrence of a disease. Cohort studies provide a measure of attributable
risk, which is the difference in the incidence of disease between
oral contraceptive users and nonusers. The attributable risk does
provide information about the actual occurrence of a disease in
the population. For further information, the reader is referred
to a text on epidemiologic methods.
Thromboembolic Disorders And Other Vascular Problems
Myocardial Infarction
An increased risk of myocardial infarction has been
attributed to oral contraceptive use. This risk is primarily in
smokers or women with other underlying risk factors for coronary-artery
disease such as hypertension, hypercholesterolemia, morbid obesity,
and diabetes. The relative risk of heart attack for current oral
contraceptive users has been estimated to be two to six. The risk
is very low under the age of 30.
Smoking in combination with oral contraceptive use
has been shown to contribute substantially to the incidence of myocardial
infarctions in women in their mid-thirties or older with smoking
accounting for the majority of excess cases. Mortality rates associated
with circulatory disease have been shown to increase substantially
in smokers over the age of 35 and nonsmokers over the age of 40
(Table III) among women who use oral contraceptives.
Oral contraceptives may compound the effects of well-known
risk factors, such as hypertension, diabetes, hyperlipidemias, age
and obesity. In particular, some progestogens are known to decrease
HDL cholesterol and cause glucose intolerance, while estrogens may
create a state of hyperinsulinism. Oral contraceptives have been
shown to increase blood pressure among users (see Elevated Blood
Pressure). Similar effects on risk factors have been associated
with an increased risk of heart disease. Oral contraceptives must
be used with caution in women with cardiovascular disease risk factors.
Thromboembolism
An increased risk of thromboembolic and thrombotic
disease associated with the use of oral contraceptives is well established.
Case control studies have found the relative risk of users compared
to nonusers to be 3 for the first episode of superficial venous
thrombosis, 4 to 11 for deep vein thrombosis or pulmonary embolism,
and 1.5 to 6 for women with predisposing conditions for venous thromboembolic
disease. Cohort studies have shown the relative risk to be somewhat
lower, about 3 for new cases and about 4.5 for new cases requiring
hospitalization. The risk of thromboembolic disease due to oral
contraceptives is not related to length of use and disappears after
pill use is stopped.
A two- to four-fold increase in the relative risk
of post-operative thromboembolic complications has been reported
with the use of oral contraceptives. The relative risk of venous
thrombosis in women who have predisposing conditions is twice that
of women without such medical conditions. If feasible, oral contraceptives
should be discontinued from at least four weeks prior to and for
two weeks after elective surgery of a type associated with an increase
in risk of thromboembolism and during and following prolonged immobilization.
Since the immediate postpartum period is also associated with an
increased risk of thromboembolism, oral contraceptives should be
started no earlier than four to six weeks after delivery.
Cerebrovascular Diseases
Oral contraceptives have been shown to increase both
the relative and attributable risks of cerebrovascular events (thrombotic
and hemorrhagic strokes), although, in general, the risk is greatest
among older (>35 years), hypertensive women who also smoke. Hypertension
was found to be a risk factor, for both users and nonusers, for
both types of strokes, while smoking interacted to increase the
risk for hemorrhagic strokes.
In a large study, the relative risk of thrombotic
strokes has been shown to range from 3 for normotensive users to
14 for users with severe hypertension. The relative risk of hemorrhagic
stroke is reported to be 1.2 for nonsmokers who used oral contraceptives,
2.6 for smokers who did not use oral contraceptives, 7.6 for smokers
who used oral contraceptives, 1.8 for normotensive users and 25.7
for users with severe hypertension. The attributable risk is also
greater in older women.
Dose-related Risk of Vascular Disease
from Oral Contraceptives
A positive association has been observed between the
amount of estrogen and progestogen in oral contraceptives and the
risk of vascular disease. A decline in serum high-density lipoproteins
(HDL) has been reported with many progestational agents. A decline
in serum high-density lipoproteins has been associated with an increased
incidence of ischemic heart disease. Because estrogens increase
HDL cholesterol, the net effect of an oral contraceptive depends
on a balance achieved between doses of estrogen and progestogen
and the nature and absolute amount of progestogen used in the contraceptive.
The amount of both hormones should be considered in the choice of
an oral contraceptive.
Minimizing exposure to estrogen and progestogen is
in keeping with good principles of therapeutics. For any particular
estrogen/progestogen combination, the dosage regimen prescribed
should be one which contains the least amount of estrogen and progestogen
that is compatible with a low failure rate and the needs of the
individual patient. New acceptors of oral contraceptive agents should
be started on preparations containing the lowest estrogen content
which provides satisfactory results in the individual.
Persistence of Risk of Vascular Disease
There are two studies which have shown persistence
of risk of vascular disease for ever-users of oral contraceptives.
In a study in the United States, the risk of developing myocardial
infarction after discontinuing oral contraceptives persists for
at least 9 years for women aged 40 to 49 years who had used oral
contraceptives for five or more years, but this increased risk was
not demonstrated in other age groups. In another study in Great
Britain, the risk of developing cerebrovascular disease persisted
for at least 6 years after discontinuation of oral contraceptives,
although excess risk was very small. However, both studies were
performed with oral contraceptive formulations containing 50 micrograms
or higher of estrogens.
Estimates Of Mortality From Contraceptive
Use
One study gathered data from a variety of sources
which have estimated the mortality rate associated with different
methods of contraception at different ages (Table IV). These estimates
include the combined risk of death associated with contraceptive
methods plus the risk attributable to pregnancy in the event of
method failure. Each method of contraception has its specific benefits
and risks. The study concluded that with the exception of oral contraceptive
users 35 and older who smoke and 40 and older who do not smoke,
mortality associated with all methods of birth control is below
that associated with childbirth.
The observation of a possible increase in risk of
mortality with age for oral contraceptive users is based on data
gathered in the 1970's – but not reported until 1983. However,
current clinical practice involves the use of lower estrogen dose
formulations combined with careful restriction of oral contraceptive
use to women who do not have the various risk factors listed in
this labeling.
Because of these changes in practice and, also, because
of some limited new data which suggest that the risk of cardiovascular
disease with the use of oral contraceptives may now be less than
previously observed, the Fertility and Maternal Health Drugs Advisory
Committee was asked to review the topic in 1989. The Committee concluded
that although cardiovascular disease risks may be increased with
oral contraceptive use after age 40 in healthy nonsmoking women
(even with the newer low-dose formulations), there are greater potential
health risks associated with pregnancy in older women and with the
alternative surgical and medical procedures which may be necessary
if such women do not have access to effective and acceptable means
of contraception.
Therefore, the Committee recommended that the benefits
of oral contraceptive use by healthy nonsmoking women over 40 may
outweigh the possible risks. Of course, women of all ages who take
oral contraceptives, should take the lowest possible dose formulation
that is effective.
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