What effect do GnRH agonists have on the reproductive HPA axis?
GnRH agonists are stimulatory if given as pulses, inhibitory if given continuously
What effect does anastrozole have on the female HPA axis?
It is an aromatase inhibitor that prevents estrogen formation from androgens
What is the mechanism of action and result of finasteride administration?
It is an reductase inhibitor that blocks the conversion of testosterone to dihydrotestosterone
How do the clinical uses of leuprolide differ depending on the way in which it is administered?
Leuprolide is a gonadotropin-releasing hormone agonist when dosed in a pulsatile fashion and a gonadotropin-releasing hormone antagonist when dosed continuously
What adverse effects are associated with leuprolide use?
Antiandrogenic actions, nausea, and vomiting
Name three common clinical uses for leuprolide.
Infertility (pulsatile), prostate cancer (continuous, used with flutamide), and uterine fibroids
Is leuprolide dosed in a pulsatile or continuous fashion for the treatment of prostate cancer? Why?
Leuprolide is given continuously to inhibit gonadotropin-releasing hormone; this decreases circulating androgens that can stimulate prostate adenocarcinoma
How can testosterone be used to treat hormonal deficiencies?
Administration of testosterone can be used in hypogonadism and to help develop secondary sexual characteristics
What is the role of testosterone in patients who have suffered from a burn?
Testosterone stimulates anabolism, which helps promote recovery from burns or other severe injuries
What role can testosterone play in the treatment of a malignancy generally seen in women?
Testosterone can be used to treat estrogen receptor-positive breast cancer
What genital exam finding would you expect in a male using exogenous testosterone?
Testicular atrophy; because exogenous testosterone blocks the release of luteinizing hormone, intratesticular testosterone will decrease, causing testicular atrophy
How would exogenous testosterone affect the height of a child that has not completed puberty?
This child may be shorter than expected because of premature closure of the epiphyseal plates
What serum lipid panel findings would you expect in a patient who has been taking testosterone?
Elevated low-density lipoprotein and decreased high-density lipoprotein
What is the mechanism of action of finasteride?
Finasteride is a reductase inhibitor, which blocks the conversion of testosterone to the more potent dihydrotestosterone
What is the mechanism of action of flutamide?
Competitive testosterone receptor antagonist
Name two drugs that function as antiandrogens as an additional effect of their interference with steroid signaling.
Ketoconazole (an antifungal) blocks desmolase, decreasing steroid synthesis; spironolactone (a diuretic) blocks steroid binding
What are two adverse effects common to both ketoconazole and spironolactone?
Gynecomastia and amenorrhea
Flutamide is used to treat what condition?
What antiandrogenic drugs can be used to treat the hirsutism associated with polycystic ovarian syndrome?
Ketoconazole or spironolactone
What are the mechanisms of action of ethinyl estradiol, diethylstilbestrol, and mestranol?
Binding to estrogen receptors and acting as agonists
Name four conditions in women that are treated with estrogens.
Hypogonadism, ovarian failure, menstrual abnormalities; and as hormone replacement therapy in postmenopausal women
Name a condition in elderly men that can be treated with estrogens
Androgen-dependent prostate cancer
What are the adverse effects of treatment with exogenous estrogens?
An increased risk of endometrial carcinoma, abnormal uterine bleeding in postmenopausal women, and hypercoagulability
You diagnose a woman with clear-cell adenocarcinoma of the vagina; what should you ask about in her history?
In utero exposure to diethylstilbestrol
Name two conditions that are contraindications to estrogen therapy.
Estrogen receptor-positive breast cancer and a history of deep vein thrombosis
How does the interaction of clomiphene at the hypothalamus result in an increase in ovulation?
Clomiphene is a partial estrogen receptor agonist at the hypothalamus, blocking negative feedback on luteinizing hormone and follicle-stimulating hormone; elevated follicle-stimulating hormone and luteinizing hormone cause increased ovulation
What are two primary clinical uses for clomiphene?
The treatment of infertility and polycystic ovarian syndrome
What are four adverse effects associated with clomiphene use?
Hot flashes, ovarian enlargement, multiple simultaneous pregnancies, and visual disturbances
How is tamoxifen used in breast cancer?
Because it acts as an estrogen antagonist in the breast, it is used to treat and prevent recurrences of breast cancer in estrogen receptor-positive tumors
Which selective estrogen receptor modulator reduces the resorption of bone and is used to treat osteoporosis?
Raloxifene; it acts as an estrogen receptor agonist in bones