Drugs for reproductive system Flashcards

1
Q

What hormone are involved in reproductive pharmacology?

A

GnRH = released by hypothalamus (pulsatile)

LH, FSH = released by anterior pituitary

Inhibin = inhibits anterior pituitary

Oestrogen

Progesterone

Testosterone

DHT

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2
Q

Explain the role/mechanism of hypothalamic pituitary gonadal axis in women (how eostrogen/proge produced)

A

Hypothalamus —> GnRH –> Ant pit –> FSH + LH –> ovary –> follicle releases oestrogen, corpus luteum releases progesterone –> inhibit ant pit (both), hypothalamus (progesterone only)

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3
Q

Explain the role/mechanism of hypothalamic pituitary gonadal axis in men(how testosterone produced)

A

Hypothalamus –> GnRH –> Ant Pit –> FSH and ICSH –> stimulate sertoli cells (FSH) and interstitial cells (ICSH) –> interstitial cells produce testosterone –> testosterone stimulates sertoli cells or becomes dihydrotestosterone

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4
Q

What are the physiological effects of oestrogen?

A

Growth of vaginal epithelium

Growth of endometrium

Lowers plasma cholesterol

behavioural effects

Liver synthesis of transport proteins

inc blood coagulability

Maintains skin structure

reduces bowel motility

Dec rate of bone resorption

Ovarian follicle

mammary gland

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5
Q

What does pulsatile (low dose) GnRH stimulation do to FSH and LH?

A

Inc FSH and LH release

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6
Q

What does continuous (high dose) GnRH stimulation do to FSH and LH?

A

Dec FSH and LH release

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7
Q

List the relevant GnRH agonists used in reproductive pharmacology

A
  • end in -relin

Goserelin

Leuprorelin

Nafarelin

Triptorelin

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8
Q

What is the MOA of GnRH agonists?

A

GnRH causes initial stimulation of FSH and LH

Continuous administration –> negative feedback –> dec FSH and LH and ICSH —> dec oestrogen, dec testosterone

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9
Q

What are the indications for GnRH agonists?

A

Precocious puberty in boys/girls

Prostate cancer, breast cancer, endometriosis

uterine fibrosis

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10
Q

What are the endogenous oestrogens?

A

Oestrone

Oestradiol

Oestriol

Not typically active

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11
Q

What are the synthetic steroid oestrogens?

A

Ethinyloestradiol

Mestranol

Tibolone

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12
Q

What are the synthetic non steroidal oestrogens?

A

Diethystilbosterol

Hexestrol

Dienestrol

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13
Q

What is the MOA of oestrogen?

A

Oestrogen –> binds oestrogen receptor (ERalpha and ERbeta)–> forms GR dimer –> crosses into lipid membrane –> binds to response element –> enters nucleus –> gene transcription and translation

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14
Q

What are the differences between oestradiol, oestrone, and oestriol?

A

oestradiol = principle oestrogenic hormone

Oestrone - metabolite of oestradiol, 1/3rd as active as oestradiol
- primarily present after menopause
- generated from androstenedione in peripheral tissue

oestriol - oestradiol metabolite
- sig less potent than oestradiol

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15
Q

Outline some of the pharmacokinetic properties of oestrogens?

A

Natural oestrogens –> inactive orally due to hepatic metabolism (need esterification or conjugation)

In circulation –> bound to sec steroid binding globulin, distributed and concentrated in fat

Undergo enterohepatic cycling = conjugated metabolites –> excreted in bile –> converted to free oestrogens by intestinal bacteria

Conjugated equine oestrogen = undergo little 1st pass metabolism, converted hepatically to sulfate and glucuronide conjugates

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16
Q

What is the most common oestrogen used in HRT?

A

estradiol

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17
Q

What are some ADRs of oestrogens?

A

Nausea (dose dependent)

For males in prostate cancer = suppression of libido, gynaecomastia, feminisation

Cholestatic jaundice, Thromboembolism, Hypertension, Migraine headache

Vaginal and cervical carcinoma

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18
Q

What are the C/I and Cautions for oestrogen use? (think diff than PPP)

A

C/I = preg, uterine fibroids

Caution = hepatic disorders, endometriosis, thromboembolic disease, hypercalcaemia

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19
Q

What drugs belong to the class of selective oestrogen receptor modulators (SERMs)?

A

Clomiphene

Tamoxifen

Raloxifene

Tibolone, bazedoxifene

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20
Q

What is the MOA of clomifene?

A

Moderate antagonist, weak agonist

Binds to the oestrogen receptors on hypothalamus and pituitary —> inhibits oestrogen mediated negative feedback of HPA —> stimulate release of LH and FSH

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21
Q

When is clomiphene primarily used?

A

Anovulatory infertility

Also effective in fertility associated with PCOS

Tx typically started at around day 5 of the cycle

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22
Q

What are the ADRs of clomifene?

A

polycystic overaies

Multiple pregnancies

Hot flushes

Gastric upset

Inc risk of ovarian cancer

23
Q

What is tamoxifen and how does it work?

A

Both oestrogenic and antioestrogenic

MOA = competes w/ oestrogen for binding to ER in breast tissue
- potent oestrogen receptor antagonist in breast carcinoma cells, blood vessels, peripheral tissues

Partial agonist in uterus, bone, liver, pituitary
- action = stimulation of endometrial proliferation, lower Gn and prolactin levels in postmenopausal women, improve bone density –> weak oestrogenic effect

24
Q

What is the primary use of tamoxifen?

A

Prevent or treat breast cancer in patients w/ ER positive tumour cells
- adjuvant to surgery or other chemo
- alone in advanced stages for palliative care

25
What are some pk properties of tamoxifen? (metabolism? enzyme genetic mutations?)
Orally active, extensively metabolically metabolised by CYP Metabolised by CYP3A4 and CYP2D6 Active metabolite 4-OH tamoxifen Less active in women lack CYP2D6 enzymes - 6-10% caucasians (underexpressed); 1-2% asians (overexpressed)
26
What effect does raloxifene have on oestrogen?
Oestrogen agonist - bone mass and lipids Oestrogen antagonist - breast and endometrium Dec bone resorption, bone turnover = inc bone density and dec vertebral fractures
27
What are some ADRs associated with tamoxifen?
Hot flushes, sweating, vomiting Vaginal bleeding, menstrual irregularities Inc risk of endometrial cancer
28
What is raloxifene mainly used for?
Prevention and treatment of postmenopausal osteoporosis Prevention of invasive breast cancer in high risk postmenopausal women
29
What are the ADRs associated with raloxifene?
Inc stroke risk, pulmonary embolism, DVT
30
What is tibolone? Where/how does it work? (oestrogenic, progestogenic, androgenic effects?)
Combined oestrogenic, progestogenic, androgenic properties Acts as oestrogen in: vagina, bone, thermoreg centres of brain Breast and endometrium = progestogenic and antiestrogenic Androgenic effects = dec HDL, TG, lipoproteins
31
What are the main uses and ADRs of tibolone?
Main use = menopausal sx and prevention of osteoporosis ADRs = vaginal bleeding, spotting, discharge and itching, breast and abdominal pain, weight gain
32
What are the effects of bazedoxifene w/ conjugated oestrogens?
Oestrogenic on bone Anti-oestrogenic on breast, uterine tissue Reduces risk = endometrial cancers associated w/ unopposed oestrogen
33
What progestin agents are similar to progesterone?
Progesterone Medroxyprogesterone acetate (they are the endogenous kinds)
34
What progestin agents are similar to 19-Nortestosterone?
19-nortesterone Norethidrone (norethisterone)
35
What progestin agents are similar to 19-Norgestrel?
Norgestrel Norgestimate etonogestrel levonorgestrel
36
What are some other progestins?
Dienogest, drospirenone Gestodene, cyproterone
37
What are the ADRs of progesterone/progestogen use?
Breast engorgement, headache, rise in body temp, oedema, mood swings Irregular bleeding or amenorrhoea 19-norethisterone derivates = inc LDL --> promote atherogenesis Inc blood sugar, precipitates diabetes Masculinization of female foetus or congenital abnormalities
38
What are the main uses for progesterones/progestins?
As contraceptive HRT Dysfunctional uterine bleeding Endometriosis
39
What is mifepristone? How/when give? What do?
19-norsteroid with potent competitive antiprogestational and significant antiglucocorticoid, antiandrogenic activity Given/MOA during follicular phase --> attenuates midcycle surge of GnRH --> slow follicular development --> failure to ovulate Given/MOA for luteal phase = prevents secretory changes brought about by progesterone Given/MOA later in cycle = blocks progesterone support to the endometrium --> unrestrains PG release --> stimulate uterine contraction
40
What are the uses of mifepristone?
Medical termination of preg Cervical ripening Cushing's syndrome
41
What is the MOA of hormonal contraceptive pill?
Oestrogen inhibits FSH sec --> suppress development of ovarian cycle Progest inhibits LH sec --> prevents ovulation and makes cervical mucus less suitable for sperm Combined = alter endometrium to discourage implantation
42
What progestogens are in the progesterone only pill?
Levonorgestrel Progesterone Dienogest Drospirenone Etonogesterel Medroxyprogesterone Norethisterone
43
What are the ADRs associated w/ progesterone only pill?
Menstrual disturbances Prolonged bleeding amenorrhea, breast tenderness depression acne
44
What is the main effect of androgens on the male sex organ, bone, kidney, muscle?
Muscle = inc strength and vol Male sex organ = penil growth, spermatogenesis, prostate growth + func Bone = accelerated linear growth, closure of epiphyses Kidney = stimulation of erythropoietin production
45
What is the role of testosterone on different tissue?
Active ligand that binds in muscle and liver Other tissues --> its metabolite DHT binds to receptors (prostate, seminal vesicles, epididymis, skin) Brain, liver, adipose tissue = biotransformed to oestradiol by CYP450 aromatase --> hormone receptor complex binds to DNA ---> synthesis of specific RNAs and proteins
46
Explain some key pk properties of testosterone
Ineffective orally --> inactivated by 1st pass metabolism
47
What are the intramuscular testosterones?
enanthate propionate cypionate isocaproate phenylpropionate
48
Outline the uses for testosterone (anabolic, endometriosis)
Danazol used in endo Anabolic effects = senile osteoporosis, chronic wasting due to HIV or cancer, burns
49
What are some ADRs associated w/ testosterones/androgens?
Virilisation and menstrual irregularities in women Acne in males and females Freq, sustained, painful erection Oligozoospermia Growth retardation, epiphysial closure Cholestatic jaundice Hepatic carcinoma gyno
50
What class does finasteride and dutasteride belong to? Explain their MOA/what do
5-alpha reductase inhibitors MOA = inhibit the conversion of testosterone to potent DHT ---> dec prostate size, growth ADRs impotence, dec libido, ejac disorders, breast tendeness
51
What testosterones are competitive androgen receptor antagonists? Where are they used?
Flutamide, bicalutamide, apalutamide, darolutamide, enzalutamide MOA = inhibit activation complexing of AR and DHT
52
What does Danazol do? (MOA, what is, ADRs)
Synthetic steroid MOA = supresses Gn secretion from pituitary both in men and women --> inhibit test/ovary function - antioestrogenic and weak androgenic - suppress gonadal funct ADRs = acne, oily skin, weight gain, hirsutism, voice change, amenorrhoea
53
What is danazol used to treat?
Endometriosis HMB Prevention of attacks of hereditary angioedema - C1 esterase inhibitor Benign fibrocystic breast disease