androgen and antiandrogens Flashcards
most important androgen hormones (endogenous)
- testosterone.
- Dihydroepiandosterone (DHEA).
- 5alphadiydrotestosterone.
- andostenedione.
physiological functions of androgens
androgenic:
- development of sec and prim sex char.
- adult women- facial, body hair, deepend voice, enlargment of clitoris, frontal baldness.
- adult male: spermatogenesis, increased libido.
- anabolic: nitro excretion reduced, protein synthesis increased, decreased protein breakdown.
steroid with anabolic and androgenic actions:
- testosterone 1:1.
- methyltestosterone- 1:1
- flouxymesterone- 1:2
- methandienone- 1:3.
- oxymetholone- 1:3
- ethylestrenol- 1:4-1:8.
- oxandrolone- 1:3-1:13
- nandrolone: 1:3-1:6
- stanozolol- 1:3-1:6.
- dromostanolone- 1:3-1:4.
indications
. 1) Male primary /secondary hypogonadism—testicular dysfunction or hypothalamus respectively.
2) Chronic wasting due to HIV or cancer.
3) Danazol- used for endometriosis or fibrocystic breast disease.
4) Danazol, stanozolol can be used for hereditary angioedema (increased C1 esterase inhibitor synthesis).
5) Illegal use in sports.
adverse
1) Masculinizing action in women and children (hirsutism, acne, deepening of voice).
2) Some androgens with progestational activity- increased cardiovascular risk, endometrial bleeding upon discontinuation in women.
3) sodium retention, edema.
4) C-17 alkyl substituted steroids (most anabolic agents)- hepatic dysfunction (hepatic tumors, cholestasis, bilirubin and increased AST).
5) Weight gain, acne, decreased breast size, depend voice, increased libido / hair growth.
adverse
contraindication:
1) Pregnancy.
2) Prostate cancer.
3) Infants and young children.
4) Breast cancer in male.
anabolic steroids
Anabolic steroids:
Synthetic androgens with higher anabolic but lower androgenic activity (1:3 ratio)- decreased virilizing effect. It has similar anabolic effect, same recetpors and same androgenic effects.
Examples include nandrolone propionate (injected) or nadrolone decanoate (injected), stanazolol and more.
Therapeutic uses include:
1) catabolic states- acute illness, severe trauma, major surgery etc.
2) Renal insufficiency.
3) Osteoporosis.
4) suboptimal growth in boys.
5) anemia: hemolytic and malignancy associated.
6) performance enhancement.
Can cause: jaundice, hepatitis, benign or malignant carcinoma of liver and oliospermia.
leuoprolide
1) androgenic suppression with GnRH-analogs- leuprolide
GnRH analogs have a longer half-life (3 hours compared with GnRH – 4 minutes), they can be given intranasally
• leuprorelin, nafarelin, goserelin, histerelin, buserelin, triptorelin
• diagnostic use:
1) delayed puberty (constitutional delay – normal LH response hypogonadotropic hypogonadism due to pituitary/hypothalamic disease – impaired LH response
therapeutic uses
1) • stimulation – pulsatile GnRH (gonadorelin) therapy: every 90 minutes – infertility caused by hypothalamic hypogonadotropic hypogonadism in both sexes
2) • suppression – continuous therapy (GnRH analogs) – prostate cancer, uterine fibroids, endometriosis, polycystic ovary syndrome, precocious puberty
3) • in vitro fertilization programs – suppression followed by exogenous gonadotropins – synchronous follicular development
steroid synthesis inhibitors
2) Steroid synthesis inhibitors- ketoconazole and abiraterone
1) ketoconazole (antifungal drug) inhibitor of adrenal and gonadal steroid synthesis: clinical trials in hirsutism (women) and prostate cancer – not encouraging • causes sexual disturbances during the antifungal treatment
2) 17-hydroxylase inhibitors: abiraterone – treatment of prostate cancer
5 alpha reductase inhibitors
3) 5-reductase inhibitors- finasteride and Dutasteride
- DHT causes hair loss and prostate enlargement.
• finasteride, dutasteride (longer acting)
• Used for BPH and baldness.
• may be useful in male baldness and female hirsutism.
4) Androgen receptor antagonists
4) Androgen receptor antagonists
4)A) bicalutamide, enzalutamide, flutamide, nilutamide
• strong and pure androgen antagonists
• used in the treatment of metastatic prostate cancer
• flutamide has a mild hepatotoxicity