8 Sex Hormones Flashcards
What are the major effects of oestradiol, progesterone and testosterone?
What are the actions and side effects of oestrogen?
What are the actions and side effects of progesterone?
What effects does testosterone have?
How well is oestrogen absorbed? Where is it metabolised? Where and how is it excreted?
How well is progesterone absorbed? Where is it metabolised? Where and how is it excreted?
What are the possible adverse effect of the COCP?
- Risk of thromboembolism slightly increased (SMOKING increases this risk substantially)
- Need to be careful about long term use and consider other risk factors eg obesity/hypertension
COCP and POP contraceptives are metabolised in the liver.
- What enzyme are they metabolised by?
- What drugs can reduce the efficacy of these oral contraceptives and how?
What effects do soya protein products have on oestrogen absorption?
Soya protein products:
- Enhance oestrogen absorption
- Reduce its storage in adipose and muscle
Reduce half-life of oestrogen
Why is HRT prescribed?
What routes are there for HRT administration?
Transdermal
Oral
Implant
Transvaginal
Nasal
What are the risks associated with HRT?
What is Mifepristone (RU486) used to treat? How does it work?
Used for: termination of pregnancy
How does it work:
- Anti-progesterone
- Progesterone (and glucocorticoid) receptor antagonist
- Sensitises myometrium to prostaglandin-induced contractions
What is a SERM? Give 3 examples of SERMs.
Selective estrogen receptor modulator
Different varying effect in differing tissues
Examples:
- Clomiphene
- Tamoxifen
- Raloxifene
What is clomiphene used to treat and how does it work?
(Clomiphene= SERM)
Used to treat: Anovulation
How it works:
- Competes with oestrogen for oestrogen receptor binding
- Ovulation induction- due to increased production of anterior pituitary hormones
Tamoxifen is a pro-drug. What does this mean?
Tamoxifen has little affinity for oestrogen receptors
Metabolised in liver- ACTIVE METABOLITES - compete with oestrogen for binding to ER
Why is it some women won’t benefit from tamoxifen and some will?
Only some women have correct isoform of enzymes in liver to metabolise tamoxifen to get active metabolites
What is tamoxifen used to treat? What effects does it have?
- Used for: prevention and treatment of breast cancer
- Effects: (converse in breast and endometrial tissue)
- Endometrium- oestrogen receptor agonist
- Breast- oestrogen receptor antagonist
- Tamoxifen (active metabolites) bind to oestrogen receptors–> arrest of cell cycle
What is the ulipristal acetate pill (ellaOne) used for and how does it work?
Selective Progesterone receptor modulator
To treat:
- Emergency contraception
- Uterine fibroids
5 Days
Name 2 HRT treatments. Why does HRT increase a person’s risk of getting a venous thromboembolism?
- Estradiol
- Oestrogen steroid hormone
- Medroxyprogesterone acetate
- Synthetic pregetogen
Increase risk of venous thromboembolism: increased thrombin activity
Name 2 drugs used as emergency contraception.
-
Levonorgestrel 3 days
- Progestogen
-
Ulipristal acetate 5 days
- Progesterone receptor modulator
Give an example of an drug containing synthetic derivatives of oestrogen.
Give an example of an drug containing synthetic derivatives of progestogen.
Why does taking testosterone increase someones risk of developing CVD?
In high doses, androgens tend to raise LDL (“bad”) cholesterol levels and lower HDL cholesterol levels
What effect do antiepileptic drugs (eg phenytoin) have on the efficacy of the COCP and POP?
Phenytoin- increases CYP450 activity- increases metabolism of COCP and POP so reduced efficacy
What are the differences between Estradiol and ethinylestradiol?
Estradiol= endogenous (natural)
Ethinylestradiol= synthetic
Ethinylestradiol- better bioavailability and less susceptible to metabolism
