Erectile Dysfunction Flashcards
Objectives
Erectile Dysfunction (ED) definition
the inability to attain and /or maintain penile etection sufficient for satisfactory sexual performance
ED Epidemiology
- Usually first emerges for men in early 40s and increases with age
- Prevalence increases with age
- 52% of men >40 years old have some degree of ED
Basic physiology of erections
- Two processes
- Cavernosal artery smooth muscle relaxation
- Increased venous outflow resistance
- High arterial inflow and low venous outflow
Cavernosal artery smooth muscle relaxation
- Active process – initial event of erection
- Parasympathetic nerves release nitric oxide →increased cyclic GMP → decreased intracellular calcium → greater smooth muscle relaxation
- Smooth muscle relaxation = arterial dilation, increased blood flow, increased intracavernosal pressure, cavernosal expansion
Increased venous outflow resistance
- Passive process
- Cavernosa expand and compress sub-tunic venous sinus
Erection phys image
ejaculation
- Sympathetic nerve release norepinephrines → stimulates alpha–1 adrenergic receptors→smooth muscle contraction →reopening venous channels→ flaccid
Erection/ ejaculation main point
- Parasympathetic = vasodilation = erections
- Sympathetic = vasoconstriction = flaccid
Etiology of ED
- Vasculogenic
- neurogenic
- psychogenic
- endocrinologic
- local penile fx
- medication induced
Etiology of ED chart
Relevant Medical PMHx for ED
- Renal failure
- diabetes
- liver failure
- alcoholism
- neurologic disease
- thyroid disorders
- atherosclerosis
Relevant Surgical PMHx for ED
- Prostatectomy
- cystectomy
- proctocolectomy
- aorto-iliac vascular surgery
- pituitary surgery
- penile surgery
- etc
Relevant Trauma PMHx for ED
- Pelvic fracture
- penile fracture
- perineal trauma
- priapism
- spinal cord injury
- pelvic radiation
Antihypertensives causing ED
- Beta blockers
- Thiazide diuretics
- Sympathetic blockers
- clonidine
- methyldopa
Antidepressants/Antipsychotics causing ED
- SSRIs
- SNRIs
- TCAs
- MAO inhibitors
- lithium
- phenothiazines
Meds that block or reduce testosterone and ED
- Cimetidine
- spironolactone
- anti-androgens
Other meds that cause ED
- Sedatives
- phenytoin
- anticholinergics
- alcohol
- smoking
ED Work-up
- Review medical, surgical, psychological, social, medications
- Onset and duration of ED
- Sustaining capability
- Penetration capability
- Nocturnal/morning erections
- Erections with masturbation
- Libido
- Ejaculatory dysfunction
- Penile curvature
- Relationship problems
- Performance anxiety
- Stress
Types of ejeculatory dysfxn
- premature
- delayed
- retrograde ejaculation
- anorgasmia
Clinical clues to cause ED Chart
ED: Physical exam work-up
- General
- body habitus
- lack or loss of normal male hair patterns
- gynecomastia
- Cardiovascular
- Auscultate heart
- femoral and peripheral pulses
- bruits
- External genitalia
- Penile plaque
- curvature
- presence of testes and their size
- Basic neuro exam
- visual fields
ED: lab work-ups
- Fasting glucose, hemoglobin A1C
- CBC/CMP – kidney and liver function
- TSH – rule out thyroid disorders
- Lipid profile – cardiac risk factors
- Serum total AM testosterone – 7-11AM
- if low, obtain FSH, LH, prolactin, repeat testosterone
- PSA
Other testing: Nocturnal penile tumescence testing
- Detects erections during REM, psychogenic versus organic causes
- Normal NPT = psychogenic…. Abnormal NPT = organic (vascular/neuro)
Other testing: Duplex doppler imaging
- Typically with injection to induce artificial injections
- Examine venous and arterial flow/velocities
Other testing: Cavernosometry/cavernosography
- Detect veno-occlusive dysfunction
- Needles places into corpora measuring pressure
- Radiographic contrast infused into corpora – visualize for venous leak
Other testing: Bilateral internal pudendal and inferior epigastric arteriography
- Internal pudendal artery supplies common penile artery supplies cavernosal artery
ED Tx
- Treatment is individualized
- Patient education
- Psychogenic
- Psychological support and counseling
- Offer testosterone if low
ED Tx general recommendations
- Avoid smoking
- Weight loss
- Exercise
- Stop alcohol abuse
- Consider medication changes
- Optimize management of diabetes, hypertension, and heart disease
ED Tx meds: PDE-5 Inhibitors
- Sildenafil
- tadalafil
- vardenafil
- avanafil
*Do not initiate an erection.. once erection is present, make erection stronger
*First line therapy, unless contraindicated
PDE-5 Inhibitors Contraindications
- CONTRAINDICATED in patient’s taking nitrates!!
- (hypotension)
PDE-5 Inhibitors Side Effects
- headache
- flushing
- blurry vision
- Most tend to lessen after several weeks of use
- Retina contains PDE-6
- inhibition of PDE-6 can cause visual side effects – tadalafil and avanafil have lowest rate of visual side effects
PDE-5 Inhibitors Diagram
Other ED Tx meds
- Alpha -2 Adrenergic Receptor inhibitor
- Yohimbine
- Prostaglandin E1
- MUSE (medicated urethral system for erections)
- Increases intracellular cAMP
- Intracavernosal Injections
- Alprostadil (prostaglandin E1)
- Phentolamine
- Combination therapies
Vacuum Erection Device Tx
- Cylindrical vacuum pump placed over penis
- Air drawn from cylinder causing blood to flow in
- Occlusive ring placed around base
Penile Prosthesis Tx
- Surgical implanation
