Pharmacology of Erection

Male Sexual Function and Dysfunction

• Erection is maintained by post-ganglionic sympathetic adrenergic nerves, which release norepinephrine as their primary neurotransmitter.
• Parasympathetic stimulation causes erection through non-adrenergic, non-cholinergic neuronal release of nitric oxide, leading to relaxation of penile smooth muscle.
• Acetylcholine, vasoactive intestinal polypeptide, cyclic GMP, and prostaglandin would result in tumescence rather than detumescence.

Urology

• In the evaluation of nongonococcal urethritis, erythromycin (500 mg four times daily) or ofloxacin (300 mg twice daily) is indicated for 10-14 days.
• Spectinomycin, ceftriaxone, amoxicillin-clavulanic acid, and penicillin are not indicated for the treatment of nongonococcal urethritis.

Metabolic Stone Evaluation

• A urine pH of 5.45 and total urinary uric acid of 368 mg/day (normal < 650 mg/day) are notable findings.
• Potassium citrate therapy can increase urinary uric acid levels.

Case Studies

• A 16-year-old phenotypic girl with primary amenorrhea and testes found on laparoscopic examination has a karyotype of 46,XY.
• The tumor most likely to develop is a gonadoblastoma if the gonads are not removed.

Erectile Dysfunction

• Vascular assessment evaluates peak systolic velocity, end-diastolic velocity, and resistive index.
• A peak systolic velocity of < 25-30 cm/sec suggests arterial insufficiency, while an end-diastolic velocity of >5 cm/sec suggests veno-occlusive dysfunction.
• A resistive index of < 0.80 suggests veno-occlusive dysfunction.

Adrenal Gland and Nerve Supply

• The nerve supply of the adrenal gland is sympathetic to medulla.
• The adrenal gland receives sympathetic innervation.

Testicular Sperm Extraction

• Assay of testosterone, LH, and FSH is not needed in a patient with a diagnosis of Kallmann syndrome.
• Testicular sperm extraction requires hormonal treatment to stimulate spermatogenesis.

Uroflow and Urodynamic Studies

• Uroflow represents the combined dynamics of the outflow tract and detrusor contractility.
• A decrease in peak uroflow may be due to either obstruction of the outflow tract, poor detrusor contractility, or both.
• There is minimal to no correlation between peak uroflow and IPSS.

Radiation Safety

• The maximum yearly dose recommended by the National Council on Radiation Protection and Measurements is 5,000 mrem or 5 rem to the entire body.
• The maximum recommended dose to a fetus is 0.5 rem, and 50 rem to an individual body organ.

Orthotopic Diversion

• CIS in the bladder, tumor at the bladder neck, and positive pelvic lymph nodes are not contraindications for orthotopic diversion.

Clitoral Anatomy

• The nerves at the mid-portion of the clitoral body are found dorsally.
• The clitoral neural anatomy is similar to that of the normal male penis.

Endocrine Neoplasia and Hypertension

• A 50-year-old man with multiple endocrine neoplasia type 2, hypertension, and an adrenal mass requires treatment for hypertension and further evaluation.

Urinary Tract Infections and Scrotal Edema

• Empiric therapy with ceftriaxone and doxycycline is indicated before laboratory test results are available.

Ileal Conduit and Stone Management

• A 1 cm stone within an ileal conduit requires further evaluation and management.
• The next step is likely endoscopy and basket removal of the stone.