4.1: Sex Steroid Hormones

Question 1

Can sex hormones cross the plasma membrane?

Answer 1

Yes as they are derived from cholesterol so are lipophilic which means they can cross the plasma membrane and bind to intracellular receptors

Question 2

What are the actions of Oestrogen?

Answer 2

Stimulate breast and endometrial growth, stimulate production of progesterone receptors, increases blood coagulability, decrease bone resorption, lowers LDL and raises HDL, increases Na and water retention, impairs glucose tolerance

Question 3

What are the actions of progesterone?

Answer 3

Stimulates breast and endometrial growth, maintains pregnancy, inhibits production of Oestrogen receptors, mood changes, increases bone mineral density

Question 4

What are some side effects of Oestrogen?

Answer 4

Nausea
Acne
Bloating due to water retention
Vomiting
Breast tenderness
Thromboembolism 
Endometrial, ovarian and breast cancer

Question 5

What are some side effects of progesterone?

Answer 5

Weight gain due to increased appetite
Nausea
Vomiting
Depression
PMS
Lack of concentration
Acne
Fluid retention

Question 6

What are the actions of testosterone?

Answer 6

Stimulates secondary male characteristics, increases aggression, promotes hair growth, voice changes, anabolism

Question 7

What are some side effects of testosterone?

Answer 7

Hair growth
Aggression
Acne
Reduced HDL: LDL ratio (hence risk of atherosclerotic disease in gender reassigned females)

Question 8

What is the mode of action of the COCP?

Answer 8

Act on the anterior pituitary for suppression of ovulation (as Oestrogen suppresses FSH, progesterone suppresses LH)
Progesterone also thickens cervical mucus and creates hostile environment for implantation

Question 9

How would CYP450 inducer drugs be tolerated in a px on the COCP?

Answer 9

As COCP is thromboembolic it is taken at its minimum effective dose, so any CYP450 inducers will increase the clearance of the COCP and so can result in contraceptive failure

Question 10

What are some examples of CYP450 inducers?

Answer 10

Rifampicin
Smoking
Anti epileptic drugs e.g. phenytoin, carbamazepine
St Johns Wort

Question 11

What forms can the progesterone only contraception be offered on?

Answer 11

POP
Implant
12 week injections depot
Vaginal ring

Question 12

What is the action of progesterone only contraception?

Answer 12

Thickens cervical mucus to prevent sperm entry

Question 13

Does the COCP act on the hypothalamus or anterior pituitary?

Answer 13

Anterior pituitary

Question 14

What are some ADRs of the COCP?

Answer 14

VTE
MI
Hypertension
Breast Ca
Cervical Ca
Headaches
Mood swings
Gallstones
Breakthrough bleeding

Question 15

When would the COCP be contraindicated?

Answer 15

Age >55
Smoker
Hypertension
Migraine with aura
BMI >35
Family Hx of VTE/ Ca
Gallstones

Question 16

When would hormone replacement therapy be prescribed for s patient?

Answer 16

For post menopausal symptoms eg. Hot flushes, vaginal dryness, osteoporosis prevention

Question 17

What is the difference between ERT and HRT?

Answer 17

ERT only replaces the Oestrogen that the body stops producing after the menopause

HRT replaces both progesterone and Oestrogen to mimic their levels prior to the menopause

Question 18

How does HRT and ERT affect risk of cancers?

Answer 18

HRT increases risk of breast Ca

ERT increases risk of endometrial and ovarian Ca

Question 19

What are some adverse effects of HRT?

Answer 19

Cancer risks
Stomach cramps
Diarrhoea
Thromboembolism
Headache

Question 20

What drug is an ovulation inducer used in IVF?

Answer 20

Clomiphene

Question 21

How does clomiphene work?

Answer 21

Inhibits Oestrogen form binding to its receptors in the anterior pituitary so inhibits the negative feedback, therefore increases levels of LH and FSH

Question 22

How does tamoxifen work?

Answer 22

Binds to Oestrogen receptors in the breast tissue to block Oestrogen stimulated cell division

Question 23

When is mifepristone, an anti progestin, used?

Answer 23

Used in medical termination of pregnancy and labour induction

Question 24

When would raloxifene, a selective Oestrogen receptor modulator, be used?

Answer 24

To protect against osteoporosis

Question 25

When would finasteride, a testosterone replacement drug, be used?

Answer 25

Used in men to prevent hair loss, male pattern baldness, and BPH

Not approved for use in women due to risk of birth defects in foetus