Endocrine-2 (Male Reproductive) Flashcards
H-P-gonad axes
GnRH
↓
LH
↓
Testes
↓
Testosterone production
————————————
GnRH
↓
FSH
↓
Testes
↓
Sperm
What is the percentage of testosterone in the testes?
95%
What are the functions of testosterone?
- Male reproductive structure development
- Maintenance of libido and erectile function
- Required for sperm maturation
Primary hypogonadism
Primary disease - problem is in the testes
Hypogonadotropic hypogonadism
Secondary disease - lack of FSH/LH from the pituitary
What are some presentations of primary hypogonadism?
- Absence of testes
- Lack of testosterone production
- Lack of functional sperm
What are some presentations of secondary hypogonadism?
- Pituitary adenomas
- Hyperprolactinemia
- Hypothyroidism
- Heavy marijuana use
What kind of drug therapy is used in primary male hypogonadism?
Testosterone replacement therapy
What are some adverse drug reactions in testosterone replacement therapy?
- Increased BP
- Major CV events
Does testosterone restore fertility?
No
What are some ways to treat secondary hypogonadism?
- Give Human Chorionic Gonadotropin (hCG)
- Give a source of FSH
What is a source of FSH that can be used to treat secondary hypogonadism?
Menotropins
What is benign prostatic hyperplasia?
A benign enlargement of the prostate gland that occurs as men age
What does prostate growth compress?
Urethra
What is LUTS?
Lower urinary tract symptoms
What are some obstructive symptoms of LUTS?
- Difficult in getting urinary flow started
- Weak urine stream
- Dribbling
- Bladder fullness
What are some irritative symptoms of LUTS?
- Frequent urination
- Urgency
- Urinary incontinence
- Nocturia
What are some complications of BPH?
- Urinary retention
- UTIs
- Irreversible impairment of bladder function
- Chronic renal failure
What are some recommended initial tests for a basic evaluation of any man with LUTS?
- Urinalysis
- Physical exam
- PSA level
- Frequency/volume charts
Is serum creatinine recommended for an initial evaluation for LUTS?
No
What is the recommended non-pharmacological treatment for LUTS?
- Watchful Waiting
- Lifestyle modifications
What are some forms of drug therapy for patients with LUTS?
Alpha-1 receptor antagonists, 5 alpha-reductase inhibitors
What is the mechanism of action of alpha-1 receptor antagonists?
Relaxes smooth muscle in the bladder neck and prostate
Is urinary flow rate increased or decreased with the use of alpha-1 receptor antagonists in patients with LUTS?
Increased
What are some examples of non-selective alpha-1 receptor antagonists?
- Terazosin
- Doxazosin
What are some examples of selective alpha-1 receptor antagonists?
- Tamsulosin
- Silodosin
- Alfuzosin
What is the mechanism of action of 5 alpha-reductase inhibitors?
Decreases conversion of testosterone to DHT
When should you follow up with patients taking 5 alpha-reductase inhibitors?
3 months
How much do 5 alpha-reductase inhibitors decrease PSA levels by?
50%
How can erectile dysfunction be classified?
Psychogenic, drug induced, or organic
How does an erection begin?
Stimulation of parasympathetic nerves
What do phosphodiesterase (PDE) enzymes metabolize?
cGMP
What is the mechanism of action of PDE-5 inhibitors?
Prevents the metabolism of cGMP
When does the initial release of nitric oxide occur?
With foreplay
What is a common product used to treat erectile dysfunction?
Tadalafil (Cialis)
What is considered an adequate trial for drug therapy treating ED?
7-8 doses
What doses is tadalafil available in?
5mg, 10mg, 20mg
What are some adverse effects of oral PDE-5 inhibitors?
- Headache
- Flushing
- Nasal congestion
- Cyanospia
What is a contraindication of oral PDE-5 inhibitors?
Any organic nitrate
- causes severe hypotension
Priapism
An erection lasting > 4hrs
What is another treatment that can be used for ED?
Alprostadil
What is the mechanism of action of alprostadil?
Stimulates adenyl cyclase, increase cGMP
What dosage forms do alprostadil come in?
- Urethral inserts
- Intracavernosal injections
Hypopituitarism
A clinical disorder characterized by diminished secretion of one or more of the pituitary hormones
What is the number one cause of hypopituitarism?
Pituitary tumors
What is the order in which the hormones are generally effected?
GH > FSH/LH > TSH > ACTH > Prl
How is hypopituitarism typically treated?
Treat the underlying cause
If hypopituitarism is not correctable, what do we do for a TSH deficit?
Levothyroxine
If hypopituitarism is not correctable, what do we do for an ACTH deficit?
Glucocorticoid
If hypopituitarism is not correctable, what do we do for a FSH/LH deficit?
Males: Testosterone
Females: Combination hormonal contraceptive
Fertility: Menotropins
