Contraception (ICM+pharm)

Question 1

Globally, what percent of pregnancies are unintended? in US?

Answer 1

Global: 41% (85 million). US: 50% Of these 41 million end in abortion, 33 million in unintended birth, and 11 million in miscarriage.

Question 2

Combined oral contraceptives: efficacy and scheduling considerations

Answer 2

Perfect use failure rate of 0.3%; typical use failure rate of 8%. Start pills on first day of menstrual cycle (1st day of menses)

Question 3

For whom is contraception NOT necessary?

Answer 3

1. 100% abstinent 2. Post-menopausal women and their partners (12 months of no menses0 3. Men and women desiring pregnancy 4. Men and women with proven infertility 5. MSM and WSW exclusively (75% of WSW have had sex with men)

Question 4

When does pregnancy begin?

Answer 4

IMPLANTATION demonstrated by positive beta-HCG. Not fertilization.

Question 5

When is the window of peak fertilization?

Answer 5

Day 10-16 is highest, but in real world its highly variable. Thats why “calendar” method isn’t ideal.

Question 6

Which methods are NOT reversible?

Answer 6

Surgical! Tubal ligation (OP) Transcervical sterilization (Fallopian tube coils- takes several months for scarring to make effective) Vasectomy (requires gen anesthesia).

Question 7

Which methods are IMMEDIATELY reversible?

Answer 7

Barrier methods, copper IUD, Calendar family planning. E/P and P only MAY be immediately reversible, but this is NOT guaranteed.

Question 8

Which contraceptive methods are most effective (typical use) (<1% failure)?

Answer 8

IUD (cu or hormonal), Prog implant, Surgical.

Question 9

Which contraceptive methods are very effective (1-10% failure)?

Answer 9

E/P pill, patch, ring, depoprivera (5%). P only pill is about 10% failure rate.

Question 10

Which contraceptive methods have failure rates above 10%?

Answer 10

Male condom (15%), diaphragm (17%), female condom (20%), natural family planning (25%), withdrawal (~26%)

Question 11

What makes a contraceptive long vs short acting?

Answer 11

How often pt has to think about it. Long is >3 months, short is <3 months (inc depo).

Question 12

Compare contraceptive cost

Answer 12

Condoms- depends on how often you have sex. Pretty expensive. E/P combo pill/patch/ring: 15-60/month IUD 300-800 dollars (lasts 3-10 years) Surgery 400-600 dollars Vascectomy is the cheapest, followed by tubal ligation, IUD, P-implant, Depot, E/P oral, Condoms, diaphragm.

Question 13

What are the delivery mechanisms for Progesterone-only methods?

Answer 13

Pill (daily, compliance MORE important than with combo); Depot (Depot modroxyprogesterone acetate injection); progesterone subdermal implant; LNG-IUD (Morena)

Question 14

Progesterone-only contraception: how does it work? (PHARM)

Answer 14

Physiologic levels are progestational, supporting luteal phase of menstrual cycle and generate secretory endometrium. Also important for suppressing menstruation /contractions during pregnancy.

Pharmacologically provides NEGATIVE feedback on LH by decreasing GnRH pulses by acting on progesterone receptors in hypothalamus. Result is thickened cervical mucus (less sperm penetration), endometrial regression, and less frequent GnRH pulses prevent ovulation.

Question 15

Progesterone (drug): side-effects

Answer 15

Androgenic: causes hair growth, acne, etc.

Question 16

Norethindrone

Answer 16

2nd generation synthetic progesterone. C17 enthinyl group is an omportant change in newer p-only contraceptives. Decreases hepatic metabolism and increases half-life.

Question 17

(levo)norgestrel

Answer 17

2nd generation synthetic. Increased half-life, lower androgenic effects than 1st gen (not as good as 3rd gen).

Question 18

“mini” pills- what is it? Who is it for?

Answer 18

Progesterone-only contraceptive pill. Less reliable than combo pills (blocks ofulation 60-80%). Useful for breastfeeding women and those for whom estrogen is CI (>35, smoker).

Depot is a more effective option for these people though.

Question 19

Progestins: CI

Answer 19

Pregnancy (obv), personal Hx of breast cancer, active thromboembolic disease (may be used if Hx only), abnormal liver function.

Question 20

Progestins- toxicity

Answer 20

menstrual bleeding/irregularity, delayed return to ovulatory function, weight gain (depot only 10-15 lbs/yr), androgenic effects, reversible glucose intolerance.

Question 21

E/P mechanism of action

Answer 21

All effects of P and Estrogen. Produces more consistent suppression of ovulation. Estrogen specifically suppresses FSH and alters Fallopian tubular transport.

Question 22

Estrogen: Indications

Answer 22

1. Hormone replacement therapy- after oophroectomy, post-menopausal releif of vasomotr instability (flushing), sleep disterbances, genital atrophy. Prevent osteoporosis.
2. Componant of contraceptive-
3. Hirsutism (hair growth), abnormal uterine bleeding, etc.

Question 23

Estradiol

Answer 23

Major secretory product of ovary. Binds to sex-hormone binding protein in plasma.

**Only free estrogens are active.

Question 24

Estradiol- Kinetics

Answer 24

Rapid biotransformation and short half-life (minutes). Enterohepatic cycling of sulfate and glucuronide conjugates in intesting. Antibiotics reduce microflora resulting in loss of cycling (and reduced drug availability).

Question 25

Ethinyl estradiol

Answer 25

Adding this C17 ethinyl group reduces first pass effect and drastically reduces metabolism by liver (t 1/2 is 13-27 hours vs minutes for estradiol).

This is really the only form used.

Question 26

Estrogens: major effects

Answer 26

1. Decreases bone resorption (inreases apoptosis of osteoclasts, decreases PTH effect)
2. Alterations in plasma lipids (generally favorable- inc. HDL, decrease LDL)
3. Bile- increases cholesterol secretion, dec. bile acid secretion– gallstones (not essential)
4. Coagulation of blood- inc. in Factors II, VII, IX, and X. Dec. in antithrombin II; inc. plasminogen.

Question 27

E/P combo delivery methods:

Answer 27

pill, vaginal ring, transdermal patch. All can be used continuously (without withrdawal bleed)- so you can not have quarterly menses.

Question 28

monophasic vs multiphasic vs. continuous use.

Answer 28

Monophasic- fixed dose of estrogen and progestin
Multiphasic- dose of progesterone varies throughout cycle (often lower total dose)

Continuous use: (no “off” week. Gives quarterly menses).

Note that “continuous use” formulations usually cost more. Any E/P combo can be used continuously, though multiphasics don’t work as well.

Question 29

Do women on contraceptives have periods?

Answer 29

No, they have breakthrough bleeds when they have an “off” week in the pack. There is no ovum present, just the endometrial lining.

Question 30

What is the main consideration when choosing a dose of E and P in a combo-pill?

Answer 30

Most side effects are due to estrogen, so if pt gets side effects, choose a lower estrogen option.

Question 31

Contraindications for E/P combo?

Answer 31

Cardiovascular disease, stroke, HTN (>160/90); Thromboembolic disease or hypercoagulability; abnormal liver function; PERSONAL Hx of breast cancer; Smoker >35 y/o; migraine w/ aura.

Caution in pts with fibroids, diabetes, headaches.

Question 32

Side effects of E/P combo

Answer 32

Nausea, vomiting (E); Headache (E); breast enlargement/tenderness (E); alterations in libido; melasma; acne, oily skin. hirsutism (P).

NO weight gain.

Question 33

E/P- drug interactions

Answer 33

P450 inducers will decrease half life (Rifampin); Low dose estrogen can lead to contraceptive failure; antibiotics MAY decrease enterohepatic cycling.

Question 34

Combo E/P- secondary benefits

Answer 34

Improved acne, regulation of menstrual cycle, ligher/shorter periods (anemia), improved cramps (dysmenorrhea), bone protection (anorexia), decreased risk of ovarian and endometrial cancer.

Question 35

Which barrier methods are “chemical”?

Answer 35

diaphragm (requires spermicidal jelly), sponge (place spermicide at key place), spermicides.

Note that cervical caps and condoms are PHYSICAL only.

Question 36

Side effects of barrier methods:

Answer 36

Diaphragm: increase risk of UTI
Local irritation

Question 37

Barriers: secondary benefits

Answer 37

Condoms: STI protection, decreased sensation for male premature ejaculation.

Female condom: may provide clitoral stimulation.

Question 38

When do you put on a diaphragm? Sponge?

Answer 38

Diaphragm- a few hours before sex, dont remove until 8 hours after. Sponges can stay in longer but will increase risk of UTI.

Question 39

Copper IUD: Mechanism of action

Answer 39

Primary- inhibits fertilization by reducing sperm motility and viability
Secondary- inhibits implantation (hostile endometrium)

INSTANTLY reversible

Question 40

Mechanism of LNG-IUD:

Answer 40

Progesterone local effects: inhibits ovulation, thickens cervical mucus, reduces sperm motility/viability.

Secondary- foreign object inhibits implantation

Question 41

The American College of Ob/Gyn recommends which type of contraception for young women?

Answer 41

LARCS! IUD or progesterone implant.

Question 42

IUD: Contraindication

Answer 42

ACTIVE STI; unexplained uterine bleeding; large deforming fibroids; Wilson’s disease or copper allergy (Cu only)

Question 43

IUDs: side effects

Answer 43

Uterine perforation (on insertion); expulsion (uterus can push it out); cramping (after insertion, may persist for months); PID risk (1st 30 days); Copper- heavy menses; LNG: irregular spotting.

Note: Does not INCREASE risk of ectopic pregnancy, but is so good at reducing intrauterine pregnancy that if a woman gets pregnant while on IUD, its a higher risk for ectopic.

Question 44

IUDs: Secondary benefits

Answer 44

LNG- lighter or NO menses.

Question 45

Describe the two “natural” family planning methods:

Answer 45

(1) Calendar- keep track of your cycle, know when you’re most fertile (no sex or barrier on days 8-19)
(2) Monitor natural ovulation cues: cervical mucus thins and becomes slippery at ovulation. Basal body temperature rises 0.1-0.5 degrees at ovulation and then stays up (no sex until 3 days after ovulation each cycle).

Question 46

For whom are natural methods CI?

Answer 46

Calendar method - only works for women with 28-32 day cycles

Things that interfere with cervical mucus: infection, douching, breastfeeding, perimenopause.

Question 47

What are 4 emergency contraception options:

Answer 47

1. Levonorgestrel (high-dose progesterone in 1 or 2 doses. Avail OTC for >15 in most states).
2. Ulipristal
3. Copper IUD
4. Several (4-6) combination E/P pills (not-2-late.com)

Question 48

Who should get a prescription for emergency contraception?

Answer 48

Any sexually active young person who is getting a prescription for ANOTHER form. Teens are at highest risk for making a mistake when using their contraception.

Question 49

Levonorgestrel- mechanism

Answer 49

high dose progesterone. Delays ovulation.

Question 50

Ulipristal: mechanism

Answer 50

Progesterone agonist/antagonist. Delays ovulation, alters cervical mucus and endometrium. Ulipristal is ambryotoxic in animals, so rule out pregnancy first.

Question 51

What is the window for administering emergency contraception?

Answer 51

120 hours of sexual intercourse.
Levonorgestrel is 95% effective in first 24 hours, decreases after 72 hours, less effective in obese.

Ulipristal- maintains very high effectiveness up to 120 hr

Copper IUD- maintains very high effectiveness to 120 hours.

Question 52

What will happen if you use EC in known pregnancy?

Answer 52

Levonorgestrel and E/P combo’s won’t work.

Ulipristal MAY cause abortion (but not reliable).

Question 53

What can be done medically for a patient who has a positive pregancy test?

Answer 53

Mifepristone (RU486) is a medical abortive that will work.

Question 54

Mifepristone: mechanism

Answer 54

Progesterone-receptor modulator (PRM)- receptor antagonist.

*Blocks uterine progesterone receptors= decidual breakdown- blastocyst detachment (dec. hCG).

NOT drug of choice for emergency contraception.

Question 55

Mifepristone: toxicity

Answer 55

Serious bleeding in 1-5% of patients.