Male Pharmacology Flashcards
Testosterone –> Dihydrotestosterone
5a reductase
Testosterone –> Estradiol
Aromatase
External genitalia
Hair follicles (balding)
Prostate hyperplasia
Dihydrotestosterone – Androgen receptor
Internal genitalia
Skeletal muscle
Erythropoiesis
Testosterone – Androgen receptor
Epiphyses
Bone density
Libido
Estradiol – Estrogen receptor
Testosterone Preparations
Transdermal - Testosterone
IM injection - Cypionate (Testosterone Esters)
Oral - Stanozolol (17-alkylated compounds)
Longest 1/2 life of testosterone preparations
Esters - Cypionate (IM) –> Days
Patch –> Hours
Gel –> 1 Day
Therapeutic uses of androgens
Male hypogonadism (testosterone deficiency) Goal is to mimic normal serum testosterone concentrations
SE of testosterone
Acne
Gynecomastia
Aggressive sexual behavior
**Must assess height and growth status of the patient
Other uses of androgens
- Male senescence
- Women with low testosterone
- Muscle wasting – associated with AIDS
- Blood dycrasias – (Danazol) for hemolytic anemia and idiopathic TTP
- Angioedema – 17-alkylated androgens (Stanozolol) stimulate hepatic synthesis of the esterase inhibitor
- Danazol is used for treatment of endometriosis and fibrocystic breast disease
- Improve athletic performance
What is one concern surrounding the use of testosterone in older men with pre-existing heart disease?
Two-fold increase in the relative risk of MI
Androstenedione and DHEA
Weak androgens
Increases popularity as a mean stop increase testosterone because they are treated as nutritional supplements
Adverse effects of androgen abuse
- Decreased endogenous testosterone and sperm production resulting in diminished fertility
- Decreased testicular size (after many years)
- High doses cause erythrocytosis
- Gynecomastia (testosterone converted to estrogen)
- 17-alkylated androgens cause hepatotoxicity – also more likely to increase LDL and decrease HDL
- In women and children virilization can occur
- Boys experience phallic enlargement, and women experience clitoral enlargement
- Stunting of linear growth (children)
- Psychological disorders and sudden death d/t cardiac disease
GnRH analog
Inhibits testosterone secretion by inhibiting LH secretion
Leuprolide
Therapeutic uses of Leuprolide
Treatment of advanced prostate cancer
Endometriosis
Central precocious puberty
SE of Leuprolide
Hot flashes
Decreased bone density
Vaginal dryness/atrophy in women
Erectile dysfunction in men
Nonsteroidal, competitive inhibitor of the androgen receptor
Increase LH secretion, used in conjunction with a GnRH analog
Flutamide
Therapeutic use of Flutamide
Metastatic prostate cancer
Hirsutism in women (off label)
SE of Flutamide
Galactorrhea Breast tenderness Gynecomastia Hot flashes Impotence Decreased libido Tumor flare Black box - hepatic failure
5-a reductase inhibitor (esp type II)
Blocks conversion of testosterone to dihydrotestosterone
Finasteride
Therapeutic use of 5a-reductase inhibitors (Finasteride)
Benign prostate hyperplasia
Male pattern baldness
SE of Finasteride
Impotence
Decreased libido
PGE1
Given as intracavernous injection or urethral suppository for erectile dysfunction
Alprostadil
SE of Alprostadil
Penile pain and urethral burning
PDE5 inhibitors
inhibits breakdown of cGMP –> penile engorgement
Sildenafil
Tadalafil
Vardenafil
Duration of action of PDE5 inhibitors
Sildenafil - up to 5 hours
Tadalafil - up to 36 hours
Vardenafil - up to 5 hours
SE of PDE5 inhibitors
H/A, flushing, visual disturbances (d/t PDE6 interaction)
What group of patients are PDE5 inhibitors CI in?
Patients taking nitrates –> combo could lead to extreme hypotension
