Contraceptives/ drugs acting on the Uterus Flashcards

1
Q

two types of oral contraceptives?

A
  1. Combined Oral Contraceptives:
    • contain a combination of an estrogen and a
    progestin
  2. Progestin-Only Oral Contraceptives
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

• Two major approaches to prevent pregnancy?

A
  1. Preventing ovulation

2. Impairing implantation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Major mechanism by which we can prevent ovulation?

A

• by suppressing LH and FSH release
• by preventing fluctuations in estrogen levels
How?
• provide patient with stable estrogen levels!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Estrogen component of oral contraceptives?

A

• Contain a combination of an estrogen and a progestin
• The estrogen is either ethinyl estradiol or mestranol
• Mestranol is a prodrug that is converted to ethinyl
estradiol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

• Progestins include:

A
Progestins include?
•Norethindrone 
•Norgestrel 
•Levonorgestrel 
•Desogestrel 
•Norgestimate 
•Drospirenone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Progesterone androgenic activity variance?

A
  • Almost all currently available progestins have some androgenic activity
  • Progestins vary in their androgenic activity:
  • Levonorgestrel and norgestrel: highest
  • Norethindrone: lower

• Third-generation progestins, such as desogestrel and
norgestimate: even lower

• Drospirenone: antiandrogenic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Combined oral contraceptives are available in?

A

• Combined oral contraceptives are available in monophasic, biphasic, and triphasic preparations
• Monophasic preparations contain fixed doses of estrogen and progestin in each active pill
• Biphasic and triphasic preparations contain varying
proportions of one or both hormones during the pill cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe Biphasic and Triphasic preparation?

A

• Biphasic and triphasic preparations were introduced to reduce the amount and total monthly dose of progestins, and to mimic more closely the hormonal changes of the menstrual cycle
• There is no evidence that bi- or tri-phasic oral
contraceptives are superior to monophasic oral
contraceptives, or vice-verse, in the prevention of
pregnancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Overview of low dose oral contraceptives?

A

• The combined oral contraceptives most commonly used
today are called ‘low-dose’
• They contain 35 µg of ethinyl estradiol or less
• The low hormone content has decreased adverse effects and risks
• But they are more likely to result in contraceptive
failure if doses are missed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe how most formulations are scheduled?

A

• Most of the formulations available have 21 hormonally active pills followed by 7 placebo pills to allow withdrawal
from bleeding
• This facilitates consistent daily pill intake

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe extended-cycle formulations and continuous combination regimens?

A

• Extended-cycle formulations increase the number of
hormone-containing pills to 84 days, followed by a 7-day
placebo phase
• This results in four menstrual cycles per year
• Continuous combination regimens provide hormone containing
pills for 21 days, then very-low-dose estrogen
and progestin for an additional 4-7 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

MOA of combined oral contraceptives?

A

• Combination oral contraceptives work primarily before
fertilization to prevent conception
• They act by preventing ovulation
• They suppress LH and FSH release and ovulation does not occur
• Additionally, the progestin thickens cervical mucus thus preventing sperm penetration, and induces changes in the
endometrium that impair implantation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Benefits of Combined Oral contraceptives?

A

• Reduction on the risk of endometrial cancer
• Reduction in the risk of ovarian cancer
• Improved regulation of menstruation
• Relief of benign breast disease
• Prevention of ovarian cysts
• Reduction in the risk of symptomatic pelvic inflammatory
disease
• Improvement in acne control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Oral contraceptive adverse effects overview?

A

• The consensus is that contraceptives have more
beneficial than harmful effects
• Concerns about cardiovascular toxicity initially limited the long-term use of these drugs
• The decrease in estrogen and progestin content has led to a reduction in adverse effects
• Many adverse effects (eg nausea, bloating,
breakthrough bleeding) improve spontaneously by the third cycle
• Therefore, patient education and early reevaluation are
necessary to identify and manage adverse effects in an effort to improve compliance
• Many adverse effects can be avoided by adjusting the
estrogen and/or progestin content of the oral
contraceptive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Adverse Effects First 3 slides of Oral Contraceptives?

A

Breakthrough Bleeding
• Most common adverse effect of oral contraceptives
• It is more of a problem with lower doses of estrogen
because estrogen stabilizes the endometrium

Headache
• Usually mild and transient
• However, migraine may be associated with
cerebrovascular accidents
• Women who develop migraines should stop taking the contraceptive

Insulin Resistance
• Progestins may cause insulin resistance by competing
with insulin for its receptor
• Current oral contraceptives have a low progestin content
and rarely cause hyperglycemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Adverse effects of oral contraceptives except cardiotoxicity and listed in first 3 slides?

A

Hirsutism
• Acne, oily skin and hirsutism are adverse effects of androgenic progestins
• The patient should be switched to a product with less androgenicity

Melasma
• Due to estrogen stimulation of melanocyte production

Amenorrhea
• Amenorrhea occurs in some patients

Dyslipidemia
• Most low-dose oral contraceptives have no impact on
HDL, LDL, triglycerides or total cholesterol

Carcinogenicity
• Oral contraceptives decrease incidence of endometrial
and ovarian cancer
• Their ability to induce other cancers is controversial

Depression
• Depression that requires cessation of therapy occurs in about 6% of patients treated with some preparations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

AE of oral contraceptives on cardiovascular system?

A

• Although rare, the most serious adverse effect of oral
contraceptives is cardiovascular disease
• This includes thromboembolism, thrombophlebitis,
hypertension, MI, cerebral and coronary thrombosis
• These adverse effects are most common among women who smoke and who are older than 35 years
• Estrogens increase production of factor VII, factor X and
fibrinogen, therefore increasing the risk of thromboembolic
events
• The risk is increase by obesity, smoking, hypertension and
diabetes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which antibacterial is implicated in metabolism of estrogen?

A

Liver Enzyme Induction
• Rifampin induces hepatic P450 enzymes and increases
metabolism of estrogen
• Use of a backup non hormonal contraceptive method during the course of rifampin therapy is recommended

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

List other oral contraceptive inducers?

A

Liver Enzyme Induction
• Carbamazepine, oxcarbazepine, phenytoin,
phenobarbital, primidone, topiramate, vigabatrin and
St John’s Wort are P450 inducers
• They are known to increase metabolism of oral
contraceptives

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Describe drug interaction of antibacterials on estrogen?

A

• Ethinyl estradiol is conjugated in the liver, excreted in the bile, hydrolyzed by intestinal bacteria, and reabsorbed as
active drug
• Certain broad-spectrum antibiotics, by reducing the
population of intestinal bacteria, may interrupt the
enterohepatic circulation of estrogen
• This may decrease estrogen levels
• Various antibiotics have been reported to decrease
contraceptive efficacy
• However, the only antibiotic for which there is evidence
that it substantially lowers steroid levels is rifampin
• Women using combined oral contraceptives should be informed about the small risk of interactions with
antibiotics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

List the absolute contraindications of mixed oral contraceptive

A
  • Pregnancy
  • Thrombophlebitis or thromboembolic disorders
  • Stroke or coronary artery disease
  • Cancer of the breast
  • Undiagnosed abnormal vaginal bleeding
  • Estrogen-dependent cancer
  • Benign or malignant tumor of the liver
  • Uncontrolled hypertension
  • Diabetes mellitus with vascular disease
  • Age over 35 and smoking >15 cigarettes daily
  • Thrombophilia
  • Migraine with aura
  • Active hepatitis
  • Surgery or orthopedic injury with prolonged immobilization
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

List the relative contraindications

A
  • Migraine without aura
  • Hypertension
  • Heart of kidney disease
  • Diabetes mellitus
  • Gallbladder disease
  • Cholestasis during pregnancy
  • Sickle cell disease (S/S or S/C type)
  • Lactation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Contents of progestin only pills?

A
  • Not widely used in the US

* Contain norethindrone or norgestrel

24
Q

Effects of progestin only pills?

A

• Slightly less effective than combined oral contraceptives
• No risk of thromboembolic events
• Other benefits: decreased dysmenorrhea, decreased
menstrual blood loss and decreased premenstrual
syndrome symptoms
• Unscheduled bleeding and spotting are common

25
Q

Progestin only pills MOA?

A

• Progestin-only pills are highly efficacious but block
ovulation in only 60% to 80% of cycles
• Their effectiveness is thought to be due largely to a thickening of cervical mucus, which decreases sperm penetration, and to endometrial alterations that impair implantation

26
Q

List 5 non oral progestin contraceptive methods?

A
  • The Patch
  • The Ring
  • The Progestin Injection
  • The Progestin Implant
  • The Intrauterine Systems
27
Q

Describe the Contraceptive patch?

Describe the Contraceptive Ring?

A

• Transdermal patch that contains both ethinyl estradiol and a progestin

• Transvaginal delivery system that delivers ethinyl
estradiol and a progestin

28
Q

Depo-provera overview and AE?

A

Depo-Provera®
• Progestin-only injectable contraceptive
• Contains depot medroxyprogesterone acetate (DMPA)
• Given IM every 3 months
• Extremely effective

• Progestin diffuses out over time to provide a circulating
level that prevents ovulation through negative
feedback
• High incidence of menstrual irregularities and weight gain
• Causes significant loss of bone mineral density
• A black-box warning cautions against the risk of
potentially irreversible BMD loss associated with longterm
use

29
Q

Describe Progestin Implants?

A
  • Single 4 cm long implant, containing a progestin
  • Placed under the skin of the upper arm using a preloaded inserter
  • Effective for 3 years
  • Major adverse effect: irregular menstrual bleeding
30
Q

Describe Intrauterine system

A
  • Levonorgestrel-releasing intrauterine system
  • It has a polyethylene body with a levonorgestrel reservoir
  • Effective for 5 years
31
Q

Other non-oral contraceptive methods?

A
  • Barrier Contraceptives
  • Condoms
  • Diaphragms
  • Cervical Caps
  • Spermicides
  • Intrauterine Devices (IUD)
  • Fertility Awareness-Based Methods
  • Sterilization
32
Q

Describe Plan B and Next Choice?

A
  • Both Plan B® and Next Choice® contain two tablets of levonorgestrel
  • The first tablet is taken within 72 hours of unprotected intercourse and the second 12 hours later
  • Adverse effects include nausea and vomiting
  • Available without a prescription for consumers ≥17
33
Q

Describe Plan B one step?

A

Plan B One-Step®
• Plan B One-Step® contains one tablet of levonorgestrel
to be taken within 72 hours after unprotected intercourse
• Available without a prescription for consumers ≥17

34
Q

Describe Ella

A

Ella®
• Ella® contains ulipristal acetate
• Ulipristel acetate is a selective progesterone receptor
modulator (SPRM)
• It acts as a progesterone antagonist to inhibit or delay
ovulation
• A single tablet is taken within 5 days after intercourse
• Adverse effects are similar to those of levonorgestrel
• Available only by prescription

35
Q

Emergency postcoital contraception hormonal methods guidelines?

A

• Emergency postcoital contraception is used to prevent pregnancy after unprotected sexual intercourse
• There are hormonal and non-hormonal methods of FDAapproved
emergency contraception
• Many norgestrel- or levonorgestrel-containing oral contraceptives can be used in high doses for emergency
contraception
• They are most effective when taken within 72 hours of unprotected intercourse

36
Q

Copper IUD timeframe?

A

• The copper IUD is also an approved method of
emergency contraception
• It has to be inserted within 5 days of intercourse

37
Q

Overview of cervical ripening?

A

• The goal of cervical ripening is to reduce the rate of failed induction
• Pharmacologic agents for cervical ripening are used when induction is indicated and the status of the cervix is
unfavorable
• Drugs used for cervical ripening are the prostaglandins dinoprostone and misoprostol

38
Q

Diniprostine and Misoprostine overview, pk, and ae?

A

• Dinoprostone and misoprostol ripen the cervix by several mechanisms
• Additionally, they stimulate uterine contractions
• They are administered to promote cervical ripening in
women with unfavorable cervixes
• This alone initiates labor in many women, and
obviates the need for oxytocin
Dinoprostone
• Synthetic preparation of PGE2
• Available as vaginal insert, and cervical gel
Misoprostol
• PGE1 analog
• Can be administered intravaginally, orally or sublingually

AE
• Tachysystole • Fever • Chills • Vomiting • Diarrhea

39
Q

Oxytocin overveiw

A

Oxytocin is the preferred pharmacologic agent for
inducing labor when the cervix is favorable or ripe
• A ripening agent should be used before oxytocin in
women with unfavorable cervixes
• Peptide hormone, secreted by the posterior pituitary
• Elicits milk ejection in lactating women
• During the second half of pregnancy, uterine smooth
muscle becomes increasingly sensitive to the stimulant
action of endogenous oxytocin
• In pharmacologic doses oxytocin can be used to induce uterine contractions and maintain labor

40
Q

Oxytocin MOA? Administration?

A

• Oxytocin acts via Gq protein coupled receptors
• Activation of oxytocin receptors leads to activation of phospholipase C and release of calcium from the SR
• Activation of oxytocin receptors also activates voltagegated
Ca2+ channels
• Ca2+ activates MLCK resulting in myometrial contraction
• Oxytocin also increases prostaglandin synthesis, which further stimulates uterine contractions
• For labor induction oxytocin is most commonly given as an IV infusion

41
Q

Oxytocin AE?

A

• Serious toxicity is rare
• Excessive stimulation of uterine contractions before
delivery can cause fetal distress, placental abruption, or uterine rupture
• High concentrations of oxytocin can activate vasopressin receptors and thus cause excessive fluid retention, or water intoxication, leading to hyponatremia, heart failure,
seizures, and death

42
Q

Management of Postpartum Hemorrhage?

A

• Uterine atony is the most common cause of postpartum
hemorrhage
• Managed with uterine massage and oxytocic drugs
• Oxytocic agents used in the management of postpartum hemorrhage include:
• Oxytocin (first-line, given IV or IM)
• Ergot alkaloids
• Prostaglandins

43
Q

Methylergonovine overview?

A
  • Partial agonist at a-adrenergic receptors and some serotonin receptors
  • The sensitivity of the uterus to the stimulant effects of ergot alkaloids increases dramatically during pregnancy
44
Q

Methylergonovine AE?

A
  • Severe adverse effects are minimal
  • Adverse reactions may include:
  • Hypertension
  • Headache
  • Nausea
  • Vomiting
  • Chest pains
45
Q

Methylergonovine contraindications?

A
  • Contraindications:
  • Angina pectoris
  • Myocardial infarction
  • Pregnancy
  • Cerebrovascular accident
  • Ischemic attack
  • Hypertension
46
Q

Overview of two prostaglandins used for postpartum hemorrhage?

A

Carboprost Tromethamine
• PGF2a analog
• Given IM

Misoprostol
• PGE1 analog
• Given vaginally or orally

47
Q

guidelines for tocolytic therapy?

A

• Labor that begins before 37 weeks of gestation is
considered preterm
• Preterm birth is the leading cause of neonatal mortality in
the US
• Management of preterm labor typically includes bed rest, tocolytics and glucocorticoids (if gestational age is <34 weeks)
• The primary purpose of tocolytic therapy is to delay
delivery to allow glucocorticoids given to the mother to achieve their maximum effect
• Glucocorticoids accelerate maturation of fetal lungs and
decrease risk of neonatal respiratory distress syndrome,
intracranial bleeding, and mortality
• The most common tocolytic agents used for the treatment
of preterm labor are magnesium sulfate, indomethacin,
and nifedipine
• There is no tocolytic of first choice

48
Q

List uterine relaxants(tocolytics)

A
  • Magnesium Sulfate
  • Indomethacin
  • Nifedipine
  • Atosiban
  • b2-adrenoceptor agonists
49
Q

Magnesium sulfate overview and adverse effects?

A

• Widely used as the primary tocolytic agent
• It has similar efficacy to terbutaline with far better
tolerance
• Magnesium sulfate uncouples excitation-contraction in
myometrial cells through inhibition of cellular action
potentials
• The mother should be monitored for toxic effects, such as respiratory depression or cardiac arrest
• Magnesium sulfate crosses the placenta and may lead to respiratory and motor depression of the neonate

50
Q

Indomethacin Overview?

A

• Prostaglandins stimulate uterine contractions during
normal labor
• Therefore NSAIDs are used to delay preterm labor
• Indomethacin is the main NSAID for this use
• Infrequent maternal side effects
• Indomethacin crosses the placenta and can cause
oligohydraminos due to a decrease in fetal renal blood
flow if used for more than 48 hours
• Indomethacin can also cause premature closure or
constriction of the ductus arteriosus
• This effect is more common after 32 weeks’ gestation:
indomethacin is therefore not recommended after 32
weeks

51
Q

Nifedipine Overview?

A

• Calcium channel blocker
• Blocks entry of Ca2+ into myometrial cells, thereby
inhibiting contractility
• Effective and safe
• Compared with other tocolytics nifedipine is associated
with a more frequent successful prolongation of
pregnancy
• Adverse effects include maternal tachycardia, palpitations,
flushing, headaches, dizziness, and nausea

52
Q

Atosiban moa?

A
  • Competitive antagonist at oxytocin receptors

* Not available in the US

53
Q

B2 adrenoreceptor agonists MOA?

A

• Activation of b2-adrenoceptors on myometrium activates
adenylyl cyclase. This causes a rise in cAMP which in turn activates PKA
• PKA phosphorylates smooth-muscle myosin light chain kinase (SmMLCK)
• Phosphorylation of SmMLCK results in a lower affinity of SmMLCK for the Ca2+-calmodulin complex
• As a result, SmMLCK dose not phosphorylate myosin,
and the myometrial smooth muscle relaxes

54
Q

B2 adrenoreceptor agonists AE?

A

• Palpitations, tremor, nausea, vomiting, nervousness,
anxiety, chest pain, shortness of breath, hyperglycemia,
hypokalemia, and hypotension
• Serious complications: pulmonary edema, cardiac
insufficiency, arrhythmias, myocardial ischemia, and
maternal death
• In February 2011, the FDA required the addition of a
Black Box Warning and Contraindication to the
terbutaline label to warn about the risk of use for preterm labor
• The decision was based on reports of deaths and serious adverse reactions following administration of terbutaline to pregnant women
• The use of injectable terbutaline should be limited to a maximum of 72 hours to treat preterm labor
• Oral terbutaline should not be used to prevent or treat
preterm labor

55
Q

List 3 abortificants?

A
  • Mifepristone (antiprogestin)
  • Misoprostol (prostaglandin analog)
  • Methotrexate (folic acid antagonist)
56
Q

2 overviews of early abortion combinations?

A

• Mifepristone is given in combination with misoprostol to
produce early abortion
• Mifepristone is administered first followed by misoprostol
24-72h later
• Major adverse effects: Cramping and diarrhea

• Methotrexate is used off-label for early abortion
• Patient is given an injection of methotrexate and
pregnancy will abort within days-weeks of injection
(similar to early miscarriage)
• Major adverse effects: Nausea and cramping