Contraception

Question 1

What are the broad categories of contraception?

Answer 1

• Medical
• Social
• Societal
• Religious

Question 2

What are the types of oral contraceptive pills?

Answer 2

• COCP (oestrogen and progestin)
• POP (progestin only

Question 3

What are the different formulations of the COCP?

Answer 3

• Monophasic
• Biphasic
• Triphasic

Question 4

What is the monophasic formulation of the COCP?

Answer 4

Each tablet contains a fixed amount of oestrogen and progestin

Question 5

What is the biphasic formulation of the COCP?

Answer 5

Each tablet contains a fixed amount of oestogen, whilst the amount of progestin increases in the second half of the cycle

Question 6

What is the triphasic formulation of the COCP?

Answer 6

The amonnt of oestrogen may be fixed or variable, whilst the amount of progestin increases in 3 equal phases

Question 7

What are the different doses of oestrogen found in the COCP?

Answer 7

50, 35, 30, or 20mg/day

Question 8

What does of oestrogen does NICE recommend in the COCP?

Answer 8

The lowest dose possible

Question 9

Give two examples of forms of oestrogen found in the COCP

Answer 9

• Ethinylestradiol
• Mestranol

Question 10

What is the half life of ethinylestradiol?

Answer 10

15 hours

Question 11

What is the half life of mestranol?

Answer 11

8-24 hours

Question 12

What are the routes of administration of COCP?

Answer 12

• Oral
• Transdermal patch
• Implants
• Nasal
• Vaginal

Question 13

What kind of oestrogens can be administered orally?

Answer 13

Synthetic derivatives; ethinylestradiol, mestranol, valerate

Question 14

What kind of progestins can be administered orally?

Answer 14

Synthetical derivavtives

Question 15

What are the types of synthetic derivatives of progestins?

Answer 15

• Progesterone derivatives, e.g. medroxyprogesterone, dyhydrogesterone
• Testosterone derivatives, e.g. norethisterone, norgestrel, ethynodiol

Question 16

What is the mechanism of action of the COCP?

Answer 16

• Suppression of ovulation
• Adverse effects on the cervical mucus
• Adverse effect on the endometrium

Question 17

How does the COCP suppress ovulation?

Answer 17

Oestrogen inhibits the secretion of FSH via negative feedback on the anteiror pituitary, and progesterone inhibits the secretion of LH

Question 18

What effect does the COCP have on cervical mucus?

Answer 18

Progesterone makes it more viscious, and therefore much less suitable for the passage of sperm

Question 19

What effect does the COCP have on the endometrium?

Answer 19

It prevents the secretory phase and so the endometrium remains atrophic - this discourages implantation

Question 20

What are the other ways that the COCP may prevent pregnancy?

Answer 20

May interfere with the cooridinated contractions of the cervix, uterus, and fallopian tubes that facilitates fertilisation and implantation

Question 21

What effect does the COCP have on the hypothalamus and gonadotroph?

Answer 21

It holds it in a ‘ready to go’ state

Question 22

What effect does the COCP have on the ovary?

Answer 22

It holds it in the ‘non-dominant follicular’ state

Question 23

What effect does the COCP have on the endometrium?

Answer 23

It holds it an the atrophic state

Question 24

What are the adverse effects of the COCP?

Answer 24

• Venous thromboembolism
• Myocardial infarction
• Hypertension
• Decrease glucose tolerance
• Increased risk of stroke in women with focal migraines
• Headaches
• Mood swings
• Cholestatic jaundice
• Increased incidence of gallstones
• Precipitate porphyria

Question 25

What is the COCP metabolised by?

Answer 25

Hepatic cytochrome P450

Question 26

What is the result of the COCP being metabolised by cytochrome P450?

Answer 26

Its efficacy can therefore be reduced by enzyme inducing drugs

Question 27

Give three examples of types of drugs that may reduce the efficacy of the COCP?

Answer 27

* Anti-epileptics * Some antibiotics * Some natural products

Question 28

Give two anti-epileptics that reduce the efficacy of the COCP?

Answer 28

* Carbamazepine * Phenytoin

Question 29

Give two antibiotics that affect the efficacy of the COCP

Answer 29

* Rifampicin * Rifabutin

Question 30

Give an example of a natural product that reduces the efficacy of the COCP

Answer 30

St. Johns Wort

Question 31

What affect do soya proteins have on oestrogen?

Answer 31

It enhances its absorption, and reduces its storage and adipose on muscle, therefore reducing the half life from 15 to 7 hours

Question 32

Why are soya proteins beneficial in post-menopausal women?

Answer 32

Because it can replace natural oestrogen

Question 33

Give 4 examples of POPs

Answer 33

* Levonorgestral * Norethisterone * Ethynodiol diacetate * Desogestrel

Question 34

Give an example of a drug used in the progesterone depot

Answer 34

Medroxy Progesterone Acetate (MPA)

Question 35

How often is MPA given in the progesterone depot?

Answer 35

Every 12 weeks

Question 36

How can the progestin etonogestrel be administered?

Answer 36

* Female implants * Male implants * Vaginal ring

Question 37

Give an example of a drug that can be used as emergency contraception up to 72 hours post coitus

Answer 37

Levonorgestrel

Question 38

Give two examples of drugs that can be used as an emergency contraception up to 120 hours after coitus

Answer 38

* Ullipristal acetate * Cu²⁺ IUD

Question 39

What is ullipristal acetate?

Answer 39

A selective progesterone receptor modulator

Question 40

How does the Cu²⁺ IUD work?

Answer 40

It prevents blastocyst attachment to the endometrium