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Flashcards in Contraceptives Deck (32)
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1

Contraceptives work by

  1. Supressing
    1. Ovulation
    2. Gametogenesis
  2. Interfering with gestation

2

Major classes of contraceptives

  • Combined oral contraceptives
  • Progestin only
    • less commonly used
  • Transdermal patch
  • Vaginal ring
  • Dermal implants
  • Intrauterine device
  • Postcoital

3

Major Estrogen analogues

  • Ethinyl estradiol
  • Mestranol
    • Pro-drug
    • 50% metabolized into ethinyl estradiol

4

Progestins 

  • Medroxyprogesterone
  • Northindrone
  • Etonogestrel
  • Levonogestrel
  • Norelgestromin
  • Norgestral
  • Norgestimate
    • the only one without ANDROGENIC activity

5

Combined oral contraceptive 

Monobasic

Constant dose estrogen and progestin

  • adminstered daily for 21 days strating from day 5 of cycle
  • During the last 7 days, this drug is substituted for a placebo and the drug can be withdrawn

6

Combined oral contraceptives 

Tribasic

  • Constant estrogen
    • Ethinyl estradiol- 30µg
    • Used to momic the menstrual cycle
  • Variable Progestins
    • Norgestrel
      • 1-6 days (50µg)
      • 7-11 days (75µg)
      • 12-21 days (125µg)

7

Progestin only pills 

Composed of

Norethindrone or norgestrel

8

Progestin only pills 

Effectiveness

Less than combied oral contraceptives

9

Progestin only pills 

Associated with

  • Iregular menstrual bleeding
  • Limited patients acceptance
    • anxiety of getting since its less effective

10

Progestin only pills 

Preferential use

  • Breast feeding 
    • Progestin does NOT prevent milk production
    • Estrogen does
  • Intolerable to estrogen
  • Smokers with existing cardiovascular complications

11

Transdermal patch composed of

Ethinyl estradiol and Norelgestromin

12

Transdermal patch applied to

The abdomen for 3 weeks. Stop for a week (bleed) and then again 

13

Transdermal patch 

Total estrogen exposure

60%> than oral contraceptives (combined)

  • Because there is no first pass metabolism
  • Less effective in obese females because there is more fat

14

Vaginal rings are composed of

Ethinyl Estradiol and Etonogestrel

15

Vaginal rings application

Taken for 3 weeks. Stopped for a week

16

Vaginal rings 

Cons

Slips

17

Progestin implants composed of

Etonogestrel

18

Progestin implants adminstered

  • 4cm capsule
  • Placed in the SubQ tissue of upper arm
  • Releases progestin for 3 years
  • If removed, effects are reversed within a month

19

Progestin itrauterine device composed off

Levonor gestrel-releasing intrauterine system

  • maintains contraception for 5 years

20

Progesrtin intrauterine device contraindicated in

  • Pelvic inflammatory disease
  • Ectopic pregnancy

21

Levonor-gestrel (0.75mg)

  • Post coital 
  • Adminstered 48-72 hours post coitus
  • 2 doses 12 hours apart

22

Ethinyl estradiol (100ug) and 0.5mg L gestrel

  • Combination
  • 2 doses 12 hours apart
  • within 48-72 hours

23

Mifepristone and Misoprostol

Mifepristone (RU 486)

  • Progestin receptor blocker
  • may induce abortion

48 hrs later...

Misoprostol

  • prostaglandin receptor analogue

 

24

MOA

  • Supress ovulation
    • Estrogen inhibits LH,FSH therefore no LH surge
    • Estrogen decreases pituitary response to GnRH
  • Progestin analogue
    • Increases thickness of cervical mucose
      • Less permeable to sperm
    • Endometrium less receptive to ovum
    • Inhibits tubular peristalsis

25

Side effects

  • CV
    • Thromboembolism
    • Thrombophlebitis
    • MI
  • Metabolic
    • Glucose intolerance
      • Predisposes to DM
        • conjugated estrogen as replacement decreases risk of T2DM
    • Weight gain
    • Serum lipids
      • E (analogue) decreases LDH and increases HDL
      • Progesterone increased LDH and decreases HDL
  • Gallblader
    • Primarily with estrogen
    • Increases cholesterol in acid causing stones

26

CI

  • CV
  • Thromboembolic disease
  • Estrogen dependent neoplasm
  • Liver disease
  • Preganncy
  • Over 35 and heavy smoker

27

Health benefits

  • Uterine fibroids
  • Functional ovarian cysts
  • Iron deficiency anemia
  • Decreases 
    • Ovarian cancer
    • Endometrial cancer
    • Acne

28

Drugs that decrease effectiveness of contraceptives

  • Rifampicin
  • Phenytoin
  • Carbamazepine
  • Chronic alcohol

Because they induce cyp450

29

Drugs that increase effectiveness and SE of contraceptives

  • Decrrease Clearance
    • Warfarin
    • Theophyline
  • Inhibit cyp450
    • Ketoconazole
    • Acetominephen

30

Gossypol

  • Male 
  • decreases spermatigenesis by destroying the cells that produce them
  • Serious SE
    • Hypokalemia
      • severe muscle weakness