Continuing Education
Contraception
Authors:
Deon T. Oliver Jr.
Pharm.D., 2015
Harrison School of Pharmacy, Auburn University
Susan P. Mixson
Pharm.D., 2015
Harrison School of Pharmacy, Auburn University
Jerry Thomason Twiggs
Pharm.D., 2015
Harrison School of Pharmacy, Auburn University
Corresponding Author:
Bernie Olin, Pharm.D.
Associate Clinical Professor and Director
Drug Information and Learning Resource Center
Harrison School of Pharmacy, Auburn University
Universal Activity #: 0178-0000-16-108-H04-P/T | 1.25 contact hours (.125 CEUs)
Initial Release Date: December 12, 2016 | Expires: December 31, 2017
Alabama Pharmacy Association
|
334.271.4222 | www.aparx.org | [email protected]
Learning Objectives
1. Describe the two primary categories of the
available contraception products.
2. List the common forms of non-hormonal
contraception.
3. List and discuss the two principle hormones
used in the hormonal contraceptive products.
4. Explain how the various special populations
of patients may be affected by hormonal
contraceptives.
5. Discuss the effectiveness rates of the
available contraceptive methods.
Introduction
Contraception is the use of various
medications and devices to prevent unplanned
pregnancy. Approximately 37% of pregnancies
in the United States are unintentional. Patients
may also use contraceptives for other reasons
including additional health benefits from
hormone-containing contraceptives and
prevention of sexually transmitted diseases from
barrier contraceptives. If the goal of
contraceptive use is to avoid unplanned
pregnancy the selection of the appropriate
method based on patient preference is important
concerning efficacy. Contraceptive methods vary
in frequency of use for efficacy. Some methods
require daily use while others involve monthly or
yearly requirements to prevent pregnancy.
Patient involvement in choosing a contraception
method and patient counseling is important for
efficacious therapy. Generally, there are two
broad categories of contraceptives, nonhormonal contraceptives and hormonal
contraceptives; these are discussed below.1
Non-Hormonal Contraceptives
(Barrier Method)
There are many forms of birth control with
varying efficacy, cost, risk, protection duration,
and capability to prevent pregnancy. Of these
choices, the most appropriate form of birth
control for a particular patient is dependent upon
a number of factors, including patient health,
frequency of intercourse, and whether or not
pregnancy is desired. The best choice for
contraception is purely a personal one. The role
of the health care professional is to provide
patients with a sufficient amount of information
to allow them to make an informed decision.
Excluding oral emergency contraceptive
products, the only forms of birth control available
over the counter are barrier methods, which
include male and female condoms, diaphragms,
sponge, and cervical caps.2- 5
What are barrier methods, and how do they
work?
Barrier methods of birth control prevent sperm
from entering the uterus and reaching the egg
for fertilization by physical or other means.
Barrier contraceptives include condoms,
diaphragms, and cervical caps; each has pros
and cons.2, 4-6
Condoms
Male Condoms
The male condom is a covering worn over the
penis during sexual intercourse that will prevent
the transport of sperm. Condoms prevent
pregnancy by acting as a physical barrier,
preventing semen from entering the vagina, thus
preventing fertilization of the female egg.
Research has shown that, in addition to
preventing pregnancy, condoms also reduce the
chance of contracting a sexually transmitted
infection (STI). They prevent the bacteria or
virus from being passed from one partner to
another. While it is true that proper use of
condoms will reduce the risk of sexual
transmitted infection (STI), the risk is never
completely eliminated because condoms are not
100% reliable. When using condoms, it is
important to read and follow the directions for
optimal effectiveness and protection.
Inappropriate use of condoms may lead to a
break or tear, which typically results in a 15%
pregnancy rate. Studies have shown that proper
use of condoms will stop pregnancy in 98 out of
100 people.4-6
Appropriate steps for using a male
condom 2, 4, 6
Step 1: Make sure the wrapper is not damaged
or opened. Also, make sure that the condom has
not reached its expiration date.
Step 2: Place the condom on the end of the
penis and ensure a good fit without too much air
trapped inside the condom.
Step 3: The next step is to unroll the condom
over the entirety of the penis and inspect for any
tears in the covering.
Step 4: After sexual contact, the condom should
be thrown away in a trash can, and never
flushed down the toilet.
Female Condoms
Female condoms, like male condoms, will
prevent sperm from reaching the egg,
preventing fertilization. Female condoms are
typically more expensive and harder to find; they
are used much less frequently than male
condoms and cost more to manufacture.
Condoms made for women typically prevent
pregnancy in 95 out of 100 women, which is a
lower percentage than condoms for men.
Studies have shown that female condoms
provide protection against pregnancy and
sexually transmitted infections; however, the
evidence is not as strong as with male condoms.
Like male condoms, improper use of female
condoms may also lead to tearing and
breakage.2
Appropriate steps for using female
condoms 2, 6
Step 1: Women can choose to insert the
condom several hours or minutes prior to
intercourse.
Step 2: Female condoms should be inserted into
the vagina and pushed in as far as possible;
making sure that it does not twist or tear during
insertion.
Step 3: These condoms should only be used
once and thrown away in the garbage, not
flushed, following intercourse.
Materials
Male condoms can be composed of several
different types of material, they may be rubber,
natural membrane, or synthetic based. The
choice of condom is primarily dependent on
patient preference, or allergies as some patients
may be allergic to latex. Latex or rubber
condoms are used most often; they provide
protection against pregnancy and STI’s and are
typically the least expensive condoms. There is
extensive evidence on the protection against
contracting HIV and other STI’s afforded by latex
condoms. Condoms that are made of natural
membranes or synthetic materials, do not have
documented evidence showing that they provide
any protection against STIs. However, natural
membrane and synthetic condoms are options
for patients whose partner has a latex allergy.2, 6
Patients should be counseled to use only
water-based lubricants such as KY jelly ®, and
avoid oil-based lubricants like Vaseline® when
using latex condoms. Studies have shown latex
condoms break more easily when used with oilbased lubricants so it is generally best to avoid
oil-based lubricant rather than run the risk of the
condom breaking. Female condoms are typically
composed of polyurethane that is safe and
allergy free for all patients. Also, female
condoms come lubricated so they typically do
not require any additional lubrication.2, 6
Diaphragms
The diaphragm is a flexible rubber cup that fits
over the cervix and is inserted into the vagina
before intercourse. The insert of the diaphragm
effectively blocks the movement of sperm into
the uterus so fertilization cannot occur. A health
care provider will find the right size diaphragm
and show patients how to use it. If a patient who
uses a diaphragm becomes pregnant, or gains
10 pounds, they should inform their doctor so
the fit can be checked. One concern with
diaphragms is that they do not prevent the
spread of STIs.2, 6
Use of diaphragms is not recommended in
women who have more than one partner,
because they are at higher risk of HIV. The good
news is that diaphragms, if taken care of
properly, will last several years. Diaphragms are
composed of either latex or silicone so they
should be avoided in women that are known to
be allergic to these materials. Also, women who
have a history of urinary tract infections, toxic
shock syndrome, or pelvic inflammation should
avoid this method of birth control as well.
Typically, 94 out of 100 women will be protected
against pregnancy, which is lower than other
forms of birth control such as condoms. It is
recommended that spermicide be used with this
method of birth control as another measure to
prevent pregnancy.2, 5, 6
Cervical Cap
The cervical cap is a small, bowl-shaped,
silicone cup that is inserted into the vagina and
fits snugly over the cervix. It is very similar to a
diaphragm, because it also prevents sperm from
reaching the cervix and is designed to be used
with spermicide. It can prevent pregnancy in 86
out of 100 women who use this form of
contraception. Also, cervical caps have been
shown to be even less effective for women who
have been pregnant before because it does not
fit as well. The problem with this birth control
method is that, like a diaphragm, it does not
protect against the spread of sexually
transmitted infections. The cap may be inserted
into the vagina for about 6 hours, but left in too
long, it may cause inflammation in the vagina
and increase the risk of infections.2, 5, 6
Sponge
The sponge is inserted into the vagina before
sex. It is typically composed of soft foam formed
into a round shape. This method of birth control
typically prevents pregnancy in 91 out of 100
women who have never given birth. However,
for women who have been pregnant the
effectiveness of this birth control method is
severally reduced. The sponge works by
preventing sperm from reaching the uterus so
the egg cannot reach the egg. This method of
contraception is an easy to use and disposable.
The Today sponge is the only sponge available
in the United States. This sponge continually
releases spermicide in an effort to enhance its
pregnancy preventing ability.2-6
Spermicides
Spermicides are chemical substances that
destroy sperm. They are an easy to use
contraceptive method that may be used alone or
in conjunction with other methods of
contraception. Spermicides are available in a
variety of forms including: cream, foam, gel,
suppository, and film. When spermicides are
used with other methods of contraception, they
can dramatically decrease the chance of an
unplanned pregnancy. It is best to apply the
spermicide at least one hour before intercourse
to ensure that it has had a chance to properly
distribute. Nonoxynol-9 is the only spermicide
that is available in the United States. Spermicide
does not provide any protection against the
transmission of sexually transmitted infections.
Women who use spermicides should be aware
that they can cause irritation and infections of
the vagina.2, 4, 6
Hormonal Contraceptives
Hormonal contraceptives, as the name
implies, makes use of synthetic hormones to
prevent pregnancy. Hormones, which are
naturally produced in the body, are essential in
preparing the uterus for implantation. The
process of preparing the female uterus for
implantation, and female “egg” maturation, is
known as the menstrual cycle. The menstrual
cycle consists of both ovulation and
menstruation. Each of these processes are
regulated by hormones.
There are two main phases of the menstrual
cycle; the follicular phase and the luteal phase.
The menstrual cycle typically lasts 28 days.
Phase progression is essentially dependent on
the concentration of hormones present. During
the follicular phase, a small group of precursor
cells (follicles) grow until one follicle dominates
and ruptures, releasing a female egg (oocyte).
After the female egg is released, it can then be
fertilized by male sperm and implanted in the
uterus; this process leads to the development of
the fetus. Also, the hormones released
throughout this process prepares the lining of
the uterus (endometrial lining) for implantation,
stops the menstrual flow, and increases the
production of cervical mucus to allow for
enhanced sperm transport.
The process during the follicular phase, where
the egg is released from the follicle is termed
ovulation. If ovulation is not complete, the egg
will not be released, and will not be fertilized.
During the luteal phase of the menstrual cycle,
the remaining follicles become what is known as
the corpus luteum, and synthesize hormones
which help to maintain the endometrial lining
and the embryo throughout pregnancy. The
corpus luteum degenerates if fertilization does
not occur. 7-8
Estrogen and progesterone both have an
important role in regulating the menstrual cycle.
Generally, there are two types of hormonal
contraceptives; those that contain a combination
of estrogen and progestin (synthetic form of
progesterone) or those with progestin alone.
Hormonal contraceptives are available in a
variety of dosage forms. In addition to oral
hormonal contraceptives, other dosage forms
include the following: transdermal patches,
vaginal contraceptive ring, and long acting
contraceptives that can be injected, implanted,
or placed in the uterus (intrauterine). It is
important to note that hormonal contraceptives
do not protect against sexually transmitted
diseases. 7-11
Combined oral contraceptives
(COC)
Combined oral contraceptive products contain a
combination of estrogen and progestin which
together work to prevent fertilization of the egg. 7
Combined oral contraceptives may be
monophasic or multiphasic. Monophasic
hormonal contraceptives have a fixed dose of
estrogen throughout the cycle, while multiphasic
contraceptives have varying doses of estrogen,
progesterone, or both throughout the cycle.
Multiphasic combined oral contraceptives
include biphasic, triphasic, and 4-phasic. 12
How do each of these hormones (estrogen
and progestin) work to prevent fertilization?
Estrogen
Estrogen has a number of functions which
help to prevent fertilization. Estrogen decreases
the release of a hormone in the body which is
essential for ovulation, follicle stimulating
hormone (FSH). FSH is released from the
pituitary gland, and plays an important role in
ovulation; it causes a surge of another hormone,
luteinizing hormone (LH) that stimulates the final
stages of follicular maturation and ovulation.
When a patient is given a contraceptive that
contains estrogen, it can decrease the amount
of FSH, which stops the LH surge, and this is
thought to decrease ovulation.7
Although, the steps mentioned above do play
a role in preventing conception, the primary role
of estrogen is stabilization of the endometrial
lining and providing menstrual cycle control.
Stabilization of the endometrial lining minimizes
breakthrough bleeding.7-9
What estrogen products are available in
combination contraceptives?
The estrogen products used in hormonal
contraceptives are a synthetic form of estrogen
that works very similarly to the natural estrogen
produced in the body. There are three synthetic
estrogens available in the United States for use
in hormonal contraceptives. Ethinyl estradiol,
mestranol, and estradiol valerate are typically
used in oral contraceptives. An additional
synthetic estrogen product, etonogestrel, is used
in hormonal contraceptive implants.7-9
What are the adverse effects of estrogen?
Like any other medication, patients on hormonal
contraceptives containing estrogen are subject
to adverse effects. The adverse effects of
estrogen are dependent on whether there is an
excess or deficiency of estrogen. Patients with
an excess of estrogen may experience the
following side effects: nausea, breast
tenderness, headache, bloating, and painful
periods (dysmenorrhea). Patients with a
deficiency of estrogen may experience these
side effects: breakthrough bleeding (spotting) on
days 1-9 of menstrual cycle, absence of period
(amenorrhea), or decreased libido (sexual
desire).7-9
Progestin
As stated above, progestin is available in
combination with estrogen, or alone, in
contraceptive products. It has a number of roles
in contraception. Progestin prevents sperm from
penetrating into the uterus by thickening cervical
mucus, slowing the transport of sperm by
making it difficult for them to swim through the
uterus to the fallopian tubes where the egg is
typically located, and changing the endometrial
lining so that it is not suitable for implantation.
Like estrogen, progestin also blocks the surge of
LH, which inhibits ovulation.7, 8, 11
What progestin products are available in
contraceptives?
A variety of synthetic progestin products are
available in the United States; these progestin
products are different based on their progestin
activity and their inherent estrogenic, antiestrogenic, and androgenic effects.7-9
Progesterone Products7-8
 levonorgestrel
 norgestrel
 ethynodiol
diacetate
 norethindrone
acetate




norethindrone
norgestimate
desogestrel
drospirenone
What are the adverse effects of progestin?
Like estrogen, the adverse effects of progestin
are dependent on whether there is an excess, or
deficiency, of progestin. If there is an excess,
patients may present with an increased appetite,
weight gain, acne, hirsutism (hair loss), oily skin,
fatigue, or depression. Patients with a deficiency
of progestin may present with breakthrough
bleeding on days 10-21 of menstrual cycle,
painful periods (dysmenorrhea), or abnormally
heavy and prolonged menstrual period
(menorrhagia).7
What are some contraindications for
combined oral contraceptives?
Use of combined oral contraceptives is not
recommended in patients that smoke tobacco,
are greater than 35 years of age, have high
blood pressure, history of blood clots
(thromboembolism), or history of certain types of
cancer (breast, liver, endometrial).11
Progesterone-only oral
contraceptives
Progestin only contraceptives are primarily used
by breastfeeding women or when estrogen is
contraindicated.
Emergency Contraceptives
Emergency contraception may prevent
pregnancy in patients that have had unprotected
intercourse, or when normal methods of
contraception have failed. Reasons for
emergency contraceptives may include the
following: no initial contraception, condom
breakage, non-adherence to contraceptive
regimen, or sexual assault. There are a few
methods available for emergency contraception.
In the United States, progestin only products are
FDA approved for use in emergency
contraception. Additional, less commonly used
methods include copper T or hormonal
intrauterine device (IUD) or use of high dose
combined hormonal contraceptives, containing
both estrogen and progesterone.7-9
There are several theories regarding how
progesterone interferes with egg fertilization. It is
thought that progestin works primarily by
delaying or inhibiting ovulation. Other evidence
shows that it may delay sperm transport.
Implantation of a fertilized egg typically occurs
within 5 days. Oral emergency contraception will
no longer be effective after the egg has been
fertilized. Evidence shows that it is best to take
these agents as soon as possible after
unprotected intercourse. Most products available
require that the emergency contraceptives be
taken within 72-120 hours of unprotected
intercourse. Patients presenting within 5-7 days
after intercourse should be referred to a
physician for an IUD.7-9
Are there adverse effects associated with
emergency contraception?
Adverse effects of emergency contraceptives
include nausea, vomiting, and irregular bleeding.
How to manage potential drug interactions
with hormonal contraceptives?
There are medications that when combined with
hormonal contraceptives have been shown to
decrease their efficacy. Patients are advised to
use non-hormonal forms of contraceptives when
on medications that interfere with their current
regimen.7
Antibiotics: Rifampin has been shown to
reduce the effectiveness of contraceptives.
Although they have not been shown to interfere
with hormonal contraceptives on a consistent
basis, additional antibiotics that may interfere
include tetracycline and penicillin classes of
antibiotics.7
Anticonvulsants: Women receiving certain
anticonvulsants should be aware that they may
affect the efficacy of their hormonal
contraceptive, particularly phenobarbital,
carbamazepine, and phenytoin. They increase
the breakdown of estrogen, which leads to
decreased efficacy.7
Dosage Forms and Failure rates 7, 10
Table 1: Contraceptive Failure Rates based on Dosage Form
Dosage Form
Description
Implants
Progestin containing rod that is inserted under the skin of
the upper arm. The progestin is released in the body over
3 years
Failure rate
0.05%
Injection
Progestin is injected into either the arm or buttocks every
three months
6%
Combined oral
contraceptives
Take orally at the same time every day. These oral
contraceptives contain a combination of estrogen and
progestin
9%
Progestin only
oral
contraceptives
Taken orally at the same time every day. These oral
contraceptives contains only progestin, as the name
implies
9%
Patch
A skin patch which may be placed on the lower abdomen,
buttocks, or upper body (with the exception of the breast).
The patch should be applied every week for 3 weeks and
removed for one week before starting a new patch.
9%
Vaginal
contraceptive
ring
Vaginal ring, placed inside the vagina, which releases
progestin and estrogen. Like the patch, the ring should be
worn for 3 weeks, then taken out for 1 week.
9%
Intrauterine
Method
(hormonal IUD)
Releases progestin hormone into the uterus. Hormonal
IUDs can be used up to 5 years.
0.2%
CDC: Reproductive health [Internet]. Atlanta: Centers for Disease Control and Prevention. Contraception; 2013 Aug 28 [cited 2014 Oct 2]; [about
10 screens]. Available from: http://www.cdc.gov/reproductivehealth/UnintendedPregnancy/Contraception.htm
NIH: Contraception and birth control [Internet]. Eunice Kennedy Shriver National Institute of Child Health and Human Development. What are the
different types of contraception?; 2012 Nov 30 [cited 2014 Oct 2];[about 8 screens]. Available from:
http://www.nichd.nih.gov/health/topics/contraception/conditioninfo/Pages/types.aspx#hormonal
Special Populations
Age
There are benefits and risks associated
with giving women over the age 35
combined hormonal contraception (CHC).
CHCs are associated with an increased risk
in cardiovascular disease and
thromboembolism (blood clots) especially in
women greater than 35 years old. Although
recent studies have suggested a low-dose
CHC may not cause an increased risk of
cardiovascular disease in women who are
healthy and not obese. Benefits include the
possibility to decrease menopausal
symptoms and increase bone density
(decreases osteoporosis risk). The risks and
benefits should be considered in each
individual patient.7, 14-15
Obesity
A decrease in efficacy of oral
contraceptives has been found in obese
patients especially with the low-dose
products. Also, patients weighing greater
than 90 kg (>198 lbs.) may experience a
decrease in efficacy of contraceptive
patches. First-line therapy should not
include patches for obese patients. Obesity
and CHCs both cause an increased risk of
venous thromboembolism (blood clots).
Therefore, women who are obese and
receiving CHCs may have an additive risk
for blood clots.7, 15
Smoking
Combined hormonal contraceptives are
contraindicated in women who smoke 15 or
more cigarettes per day and are over the
age of 35. Smoking tobacco while taking
CHCs increases the risk of myocardial
infarction (heart attack). If the patient is
unwilling to quit smoking, progestin-only
contraceptives may be considered. For
women who smoke and are less than 35
years old, CHCs should be used with
caution.7, 14
Postpartum and Lactating Women
Combination oral contraceptive (COCs)
use is recommended no sooner than 4
weeks after delivery in non-breastfeeding
mothers due to an increased risk of blood
clots during the first few weeks. Progestinonly products are a reasonable option if
contraception is needed during this time.
Lactating women should wait until 6 weeks
after delivery to use progestin-only
products. The use of COCs does not cause
harm to the breastfeeding infant. Progestinonly agents do not cause infant harm and
may even increase the quality and duration
of lactation.15
Seizure disorder
Medications used to treat seizure
disorders may decrease the amount of
combination oral contraceptives in the body,
theoretically leading to reduced efficacy.
Although, studies have found decreased
levels of oral contraceptives due to
anticonvulsants with no ovulation or
pregnancy occurring. The use of condoms
in addition to oral contraceptives is usually
recommended. Intrauterine products may
be an efficacious alternative in this
population.15
Thromboembolism
The estrogen component in combined
hormonal contraceptives increases the risk
for thromboembolism (blood clots).
Estrogen increases the production of factors
in the blood that promote clotting. Newer
agents containing the progestins
drosperinone, desogesterel, and
norgestimate have a slightly higher risk of
clotting when compared to other products.
Conditions such as obesity, pregnancy,
immobility, surgery, and hypercoagulable
states may have additive risk for
thromboembolism with concurrent oral
contraceptives.7
Breast Cancer
Oral contraceptives have been shown to
increase a women's risk of developing
breast cancer. Women with a family history
of breast cancer or benign breast disease
may receive combined hormonal
contraceptives. A patient should not use
CHCs if they have a recent, personal history
of breast cancer but CHCs can be used if
patient has been in remission for 5 or more
years.7, 15
Migraines
Women who experience migraines may
see an improvement or worsening in the
amount of migraines occurrence. Combined
hormonal contraception increases the risk of
stroke if the patient experiences migraines
accompanied with aura (warning signs such
as visual disturbances). A low-dose CHC
may be given to women presenting with
migraines without aura who are nonsmokers, less than 35 years old, and
generally healthy. Women older than 35
and/or experience migraines with aura
should not receive contraception with
estrogen.7,14
Hypertension
Combined hormonal contraceptives can
cause an increase in blood pressure (6-8
mmHg) in women with normal blood
pressure and women diagnosed with
hypertension. Hypertension induced by
CHCs develops over the first 3 to 36 months
of therapy and can take up to 6 months to
decline after discontinuation. Studies have
found an increase in risk of heart attack and
stroke in hypertensive women receiving
combined oral contraceptives. Women with
controlled hypertension may receive CHCs
but blood pressure should be monitored.
Progestin-only options are an alternative in
patients with high blood pressure.7, 14
Diabetes
Diabetic women, including Type 1 and
Type 2, may receive CHCs if they are nonsmokers, less than 35 years old, and do not
have any type of vascular disease. Women
diagnosed with diabetes or vascular disease
more than 20 years ago should not receive
combined hormonal contraceptives.7, 14-15
Summary
In summary, there are a wide variety of
contraceptives available including
nonhormonal and hormonal options. The
type of contraception used should be
decided upon based on patient specific
characteristics such as age, reason for
contraceptive use, number of sexual
partners, comorbidities, patient adherence,
and patient preference. Healthcare
providers should counsel patients on the
administration and/or use of contraceptives
as well as explain the risks and benefits
pertaining to specific products.
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