Androgen Pharmacology Flashcards
Testosterone levels fluctuate, but the daily secretion range for males is __________ and females is __________.
5 - 7 ng; 0.25 ng
Highest levels of testosterone are around ________.
8 AM (500-700 ng/dl)
Hypogonadism is considered _________.
testosterone less than 200 ng/dl
In which patients is testosterone used?
Hypogonadal boys
Patients with osteoporosis
Aging men (questionable)
AIDS patients with cachexia
Gynecomastia, low libido, and low bone density are associated with ____________.
low estrogen
Parenteral testosterone decreases spermatogenesis. Why?
It suppresses the production of LH and FSH.
Which types of testosterone have androgenic activity?
All of them. All testosterones have anabolic and androgenic activity.
The disadvantage of testosterone patches is ______________.
high frequency of skin rash (up to 1/3 of patients)
Which formula of testosterone causes the most consistent plasma level of testosterone?
Transdermal gel
A frequent side effect of oral testosterone is ________________.
hepatotoxicity (specifically cholestatic jaundice)
True or false: testosterones can cause anemia.
False. They stimulate RBC production and thus treat anemia form low EPO.
Which enzyme is inhibited by the drug that can treat ACTH-independent Cushing’s?
Ketoconazole inhibits 17-alpha hydroxylase
Why do some birth controls treat acne?
Estrogen increases the expression of sex-hormone-binding globulin which lowers the level of free testosterone. In females, there is no sensing mechanism to increase testosterone production, so the levels stay down and sebum production decreases (because sebum production is stimulated by testosterone).
What do the -lutamide drugs do?
Block androgen receptors!
Enzalutamide and bicalutamide
Which drugs block 5-alpha reductase?
Finasteride (commonly given in BPH)
What is the main benefit of using androgen receptor antagonists as opposed to the former practice of using a once daily agonist (that leads to pituitary suppression)?
The agonists have flare symptoms when given in large doses.
What two hormones are needed for spermatogenesis?
FSH and testosterone
Where does negative feedback from LH and FSH occur?
LH stimulates androgen production, which acts in negative feedback on the pituitary and hypothalamus, while FSH stimulates production of inhibin which only acts on the pituitary.
What percent of testosterone is made by the testes and adrenal glands?
Testes: 95%
Adrenal glands: 5%
When should you consider testosterone supplementation?
In men who have had multiple testosterone levels below 200 ng/dl and who are having symptoms of low testosterone (such as decreased libido, erectile dysfunction, gynecomastia, or small testes)
Why is methyltestosterone not used?
It is hepatotoxic. It has the advantage of being less affected by first-pass metabolism, but it is too toxic to use. (Specifically, it can cause cholestatic jaundice.)
What are some side effects of testosterone?
Physiologic doses have the exact same as physiologic testosterone: acne, gynecomastia, and aggression. Supraphysiologic doses cause testicular shrinkage, decreased spermatogenesis, and psychiatric disturbance.
Which adrenal enzyme is inhibited by ketoconazole?
17-alpha hydroxylase
Which suffix is found in GnRH antagonists?
-relix
Degarelix and ganirelix
