gonadal hormones and inhibitors

Gonadal Hormones and Inhibitors

Ma. Victoria Matias-Villarica, M.D.Dept. of Pharmacology

Fatima College of Medicine

Objectives:

• Review gonadal hormone secretion and their functions

• Identify the uses of these hormones

Estrogen

• Natural Estrogen a. 17-β-estradiol b. Estrone c. Estriol• Synthetic Estrogen a. Ethinyl estradiol b. Quinestrol c. Mestranol

Estrogen (cont.)• Non-steroidal Synthetic Estrogen a. Methestrol b. Dienestrol c. Benzestrol d. Hexistrol e. Diethylstilbestrol f. Chlorotrianisene g. Methallenestril• Anti-Estrogen a. Tamoxifen b. Clomiphene

Progesterone• Natural Progestin - Progesterone• Synthetic Progestin a. Norgestrol b. Medroxyprogesterone c. Norethindrone• Anti-progestin a. Danazol b. Mifepristone

Androgens• Natural Androgen - Testosterone• Synthetic Androgen a. Methyltestosterone b. Fluoxymesterone• Anabolic Steroid a. Oxandrolone b. Stanozolol

Androgens (cont.)• Androgen Antagonist a. Finasteride b. Flutamide c. Cyproterone d. Ketoconazole e. Spirinolactone

Ovary - Quiescent - Gonadarche - Menarche - Menopause - Disturbances of ovarian function: a. emotional and environmental stress b. anovulatory cycles c. organic causes – pituitary adenomas,

arrhenoblastoma, Leydig cell tumors

Estrogen:• Secreted by the theca cells, corpus luteum,

placenta and adrenals and testes• Intracellular receptors for lipid soluble agents• Bounded by SHBG• Metabolites: cathecol estrogen →

neurotransmitters → converted to 2- and 4-methoxycompounds by COMT

• Enterohepatic circulation

Estrogen: Physiologic effects

• Female maturation - stimulate the development of vagina, uterus,

uterine tubes - breast: stromal development, ductal development - growth: accelerated; closure of epiphysis of long

bones - growth of axillary/pubic hair - typical female body contour

Estrogen: Physiologic effects (cont.)

• on sexual organs (primary and secondary sexual characteristics)

• ovaries : stimulate follicular growth; small doses cause an increase in weight of ovary; large doses cause atrophy

• uterus: endometrial growth• vagina: cornification of epithelial cells with

thickening and stratification of epithelium• cervix: increase of cervical mucous with a lowered

viscosity (favoring sperm access)

Estrogen: physiologic effects (cont)

• Endometrial effects – hyperplasia with abnormal bleeding patterns

• Cardiovascular effects: - ↑HDL, ↓LDL; ↓antithrombin III; ↑ Fx II, VII, IX, X;

↑plasminogen levels, ↓platelet adhesiveness

Estrogen: physiologic effects (cont)

• Other effects: - influence behavior and libido - loss of fluid from intravascular into the extravascular space (edema) - induce synthesis of progesterone receptors

- electrolytes: retention of Na+, Cl- and water by the kidney

- cholesterol: hypocholesterolemic effect

- skin: increase in vascularization, development of soft, textured and smooth skin

- bone: increase osteoblastic activity

Estrogen: Clinical uses

• Post-menopausal hormonal therapy-reduction of MI (50%), fatal strokes (40%) -prevent fractures-0.3mg D1-D21 monthly + medroxyprogesterone

acetate-S/P hysterectomy – 5 days/week-atrophic vaginitis - topical • Oral contraceptives• Hypogonadism – 0.3mg D1-D21 monthly• Osteoporosis• Infertility• Dysmenorrhea• Prostate Ca

Natural estrogens

• Conjugated estrogenic substances:• an amorphous preparation containing water soluble

conjugated forms of mixed estrogens from the urine of pregnant mares (Premarin, Cenestin - synthetic conjugated estrogens)

• estradiol :– oral : Estrace– transdermal: Climara, Alora, Vivelle, Vivelle-Dot,

Estraderm, FemPatch

Natural estrogens

• estrone: – Kestrone 5 (injectable only)

• esterified estrogen– (75-85% sodium estrone sulfate and 6- 15%

sodium equilin sulfate)– Estratab; Menest

• estropipate (piperazine estrone sulfate)– Ogen; Ortho-Est

Natural estrogens

• Sustained-release injectables:• estradiol valerate in oil (Delestrogen; Valergen)• estradiol cypionate in oil (depGynogen; DepoGen)• duration of action from 3 to 8 weeks• esterified at C-17 hydroyl group

Estrogen products

Estrogen: Contraindications

• Estrogen dependent neoplasm (breast, endometrium)

• Undiagnosed genital bleeding• History of thromboembolic disorders• Pregnant women

Progesterone:

• Synthesized in the ovary, testes, adrenals• Produced primarily by corpus luteum• Males: 1-5mg daily or 0.03ug/dl plasma level• Kinetics: rapidly absorbes; t1/2 – 5mins;

completely metabolized in the liver

PROGESTERONE

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C

CH3

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PROGESTERONE

Natural hormone secretedby the corpus luteum and theplacenta ( a C-21 steroid) it is also an important intermediate in steroid biogenesis in all tissues that produce steroids (testes, adrenal cortex)

Intestinal absorption is quite erratic; must be micronized formost effective absorption (Prometrium)

Progesterone: Physiologic effects:

• Affects carbohydrate metabolism• Compete with aldosterone• ↑ body temperature• Breast: alveolobular development of the

secretory apparatus of the breast• Endometrium: maturation and secretory

changes• ↓plasma levels of amino acids

Progesterone: Clinical uses

• Hormonal replacement therapy• Contraception• Diagnosis: estrogen secretion• Dysmenorrhea• Endometriosis

Progesterone: CI/AE

• Increase BP• Decrease plasma HDL

Other androgens secreted by the ovary:

• Testosterone• Androstenedione• DHEA (dehydroepiandrosterone)• Inhibin• Activin• Relaxin

Testes:

• Functions: sperm production (FSH) testosterone synthesis (LH)• 8mg testosterone daily• Weak androgen: androstenedione,

dehydroepiandrosterone• Active androgen: dihydrotestosterone (5-α-reductase)• Testosterone is converted to estradiol by

p450 aromatase

Natural androgens

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TESTOSTERONE

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DIHYDROTESTOSTERONE

Testosterone: Physiologic effect

• Changes in the skin (pubic, axillary, beard)• Larynx• Skeletal growth • ↑ lean body mass• Male development• Anabolic effect on muscle and bone mass: ↑ CHON

synthesis, ↓ CHON breakdown• Other effects: erythrocyte production,

musculinization in females

Testosterone: Clinical Uses

• Androgen replacement therapy• Gynecologic disorders• Protein anabolic agent• Refractory anemia• Osteoporosis• Growth stimulators• Abused in sports• “Slows” aging

Other Uses for Androgens

• Replacement therapy in hypogonadism• delayed puberty• cryptorchidism• metastatic breast cancer in women• postpartum breast pain/engorgement• male climacteric

Testosterone: Contraindication

• Pregnant women• Ca of the prostate, breast

Adverse effect:• Musculinizing effect in women• Alteration of serum lipid profile• Hepatocellular Ca

Testosterone products

• testosterone in aqueous suspension (short-acting)

• testosterone propionate in oil • testosterone enanthate in oil (Delatestryl)• testosterone cypionate in oil (Depotest)• testosterone pellets (Testopel)• testosterone transdermal system (Androderm)

Anti-Estrogen• Clomiphene - partial agonist at estrogen receptors - act as competitive inhibitors - stimulates ovulation by preventing feedback inhibition - AE: hot flashes, eye symptoms, ovarian cyst, skin rxn,

multiple births - 50mg OD x 5days; 100mg OD x 5days; 100mg OD x

5days

Anti-Estrogen:• Tamoxifen - Act as competitive inhibitor - For breast Ca - AE: hot flashes, N and V, vulvar pruritus, menstrual

irregularities - 10-20mg BID (35% ↓ but not >5yrs)

□ Toremifene – prevent bone loss, ↓atherosclerosis; (+) uterus

□ Raloxifene - prevent bone loss, ↓atherosclerosis; (-) uterus

AROMATASE INHIBITORS• aromatase is a cytochrome P450 enzyme that catalyzes the

conversion of adrenal androgen androstenedione to estrone in both pre- amd post menopausal women

• reaction occurs in the liver, muscle, adipose and breast tissue• in post-menopausal women, aromatization is responsible for

the majority of circulating estrogen• aminoglutethimide was used but has now been replaced by

more selective drugs• drugs may be steroidal (testolactone, emestane) or non-

steroidal (anastrozole, letrozole)• estrogen deprivation through aromatase inhibition is an

effective and selective treatment for some post-menopausal patients with hormone-dependent breast cancer

AROMATASE INHIBITORS

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LETROZOLE (FEMARA)

both of these drugs are used in the treatment of advancedbreast cancer in post-menopausal women with diseaseprogression following tamoxifen therapy

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CCH3

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CH3

CH3

ANASTROZOLE (ARIMIDEX)

Exemestane (Aromasin)

• 6-methylenandrosta-1,4-diene-3,17-dione• structurally related to androstenedione• acts as an irreversible (suicide) inhibitor of aromatase• has no effect on other enzymes involved in

steroidogenesis• indicated for the treatment of advanced breast

cancer in postmenopausal women whose disease has progressed following tamoxifen therapy

Anti-Progestin• Mifepristone – RU 486 - inhibits activity of progesterone - post-coital contraceptive (600mg SD), abortifacient

(400-600mg x 4days/ 800mg/day x 2days (85%) or 600mg SD + misoprostol 1mg (95% 7wks); Cushing’s syndrome

- AE: heavy bleeding, N and V, anorexia, abd. pain

Anti-Progestin• Danazol - suppress ovarian function; inhibits mid-

cycle surge of LH, FSH - endometriosis (600mg/d) - fibrocystic dis. of the breast - AE: weight gain, edema, acne, cramps - CI: pregnancy, breastfeeding

Anti-Androgen• Finasteride – inhibits 5-α – reductase (5mg/d) - BPH(5mg/D), baldness (1mg/D)• Spirinolactone - ↓synthesis of testosterone on the

testes• Ketoconazole - ↓synthesis of testosterone on the

testes - inhibits binding to androgen receptor• Cyproterone – inhibits binding to androgen receptor - hirsutism in women, prostatic Ca• Flutamide – inhibits binding to androgen receptor - prostatic Ca 1. Bicalutamide (150-200mg/d) 2. Nilutamide (300mg/d x 3 days)

Antiandrogen drugs

Finasteride : Proscar and Propecia

Hormonal Contraceptives

• Combination oral contraceptive I. Monophasic – provide constant

amount of estrogen and progesterone (21day)

II. Biphasic – provide varying amount of progestin but constant amount of estrogen

III. Triphasic - provide varying amounts of estrogen and progestin

• Transdermal combination contraceptive

Examples of Oral Contraceptives• 4 types:

– monophasic: Loestrin, Levlen, Levora, Levlite, Desogen, Lo/Ovral, Ortho-Cept, Nordette, Demulen, Ovcon, Modicon, Zovia, Loestrin, Apri, Microgestin, Yasmin, Ortho-Cept, Levora, Alesse

– biphasic: Ortho-Novum 10/11, Nelova 10/11, Necon 10/11, Jenest-28, Mircette

– triphasic: Ortho-Novum 7/7/7, Tri-Norinyl, Tri-Levlen, Triphasil, Trivora-28, Estrostep

– progestin-only: Micronor, Nor-QD, Ovrette

Adverse effect of combination oral contraceptive:

• Mild: nausea, mastalgia, breakthrough bleeding, changes in serum protein, transient headache, withdrawal bleeding

• Moderate: breakthrough bleeding, weight gain, skin pigmentation, acne, hirsutism, vaginal infections, amenorrhea

• Severe: vascular disorders (MI, CVA), cholestatic jaundice, depression, Ca

Hormonal Contraceptive

• Progesterone only contraceptiveI. Oral: Norethindrone, NorgestrelII. Subdermal: Norgestrol, NorplantIII. Injectable: Medroxyprogesterone Acetate/

Depoprovera

• Post-coital contraceptive

OTHER CONTRACEPTIVE PRODUCTS

• Levonorgestrel implants (Norplant system)• intrauterine progesterone contraceptive

system (Progestasert)• medroxyprogesterone contraceptive injection

(Depo-Provera)• nonoxynol contraceptive creams and gels

Emergency contraceptives

• drugs used for the prevention of pregnancy following unprotected intercourse or a known or suspected contraceptive failure

• to be effective these must be taken within 72 hours of intercourse

• two products are available:– Plan B: 0.75 mg levonorgestrel– Preven: 0.25 mg levonorgestrel and 0.05 mg ethinyl estradiol (this

product includes a pregnancy test kit)

Male Contraceptive

• Gossypol – phenolic compound that reduces sperm density by 99% in men and impairs sperm motility

- 20mg/D x 2 mos. or 60mg/wk - not continued >2yrs.

In summary……

• Identify gonadal hormone secretion and their functions

• Know the uses of these hormones

Types of steroid hormones

• Glucocorticoids; cortisol is the major representative in most mammals

• Mineralocorticoids; aldosterone being most prominent

• Androgens such as testosterone • Estrogens, including estradiol and estrone • Progestogens (also known a progestins)

such as progesterone

Miscellaneous topics

Performance Enhancing Drugs

1995 poll – 198 Olympic level power athletes- Given the ffng scenario, you are offered a

banned substance with 2 guarantees: 1. you will not be caught 2. by taking the substance you will win your

event- Only 3 said NO

Same poll, new scenario:

1. the substance will allow you to win every competition you enter over the next 5 years

2. however, the substance will kill you

• More than 50% would still use the substance!

Anabolic, androgenic, and growth hormones

• Anabolic refers to muscle building (Testosterone, Dianobol, and Deca Durabolin)

• Androgenic refers to increased masculine characterictics (Equipoise, Masteron, and Trenbolone)

(2005,march NIDA Infofacts)

• Growth hormones are different in nature from

anabolic-androgenic steroids.

(2005,march NIDA Infofacts)

Georgia Bureau of Investigation at 2:30 p.m. EDT on July 17, 2007

REPRODUCTIVE HEALTH BILL IN THE PHILIPPINES

• There are four bills pertaining to reproductive health and/or population management that have been filed for deliberation in both the House of Representatives and the Senate for the 14th Congress. These are House Bill No. 17 authored by Rep. Edcel Lagman, House Bill No. 812 authored by Rep. Janette Garin, Senate Bill No. 40 authored by Sen. Rodolfo Biazon and Senate Bill No. 43 authored by Sen. Panfilo Lacson.

The bill is controversial, as it is being opposed by the Catholic Church.

The Catholic Church is against the use of artificial

contraceptives House Bill No. 17, also known as the proposed "Reproductive Health and Population

Development Act of 2008," will cover the following areas: • information and access to natural and modern family planning; • maternal, infant and child health and nutrition; • promotion of breast feeding; • prevention of abortion and management of post-abortion complications; • adolescent and youth health; prevention and management of reproductive tract

infections, HIV/AIDS and sexually transmitted diseases; • elimination of violence against women; counseling on sexuality and sexual and

reproductive health; • treatment of breast and reproductive tract cancers; • male involvement and participation in reproductive health; • prevention and treatment of infertility; and • reproductive health education for the youth.

Finally …….

The EndThank You!