1. Erectile dysfunction Flashcards
Define
The inability to attain or maintain penile erection sufficient for sexual performance.
Causes
POC:
- Psychogenic
- Organic
- Combination
Psychogenic causes
- Relationship problems
- Stress
- Anxiety
- Fear of failure (Performance anxiety)
- Feelings of inadequacy
- Depression
Mechanism of psychogenic causes
Sympathetic overactivity, leading to vasoconstriction
Organic causes
VND + PET
- Vascular
- Neurogenic
-Drugs
- Penile lesions
- Endocrine
- Trauma
Vascular
Arterial: Atherosclerosis(smoking,hypertension,obesity and cholesterol)
Venous: Venous leak
Neurogenic
- Spinal cord injury, disk prolapse, spinal cord tumour
- Autonomic neuropathy(alcoholo,diabatesmellitus)
- Multiple sclerosis
- Brain lesions (tumour, smoke)
Drugs
- Anti-hypertensives (Methyldopa, B-blocker)
- Diuretics (hydrochlorothiazide,furosemide)
- Psychotropics (SSRI’s, TAD’s)
- Recreational drugs
Penile lesions
- Peyronie’s Disease
- Priapism
Endocrine
- Decreased testosterone(Age related,bilateral orchidectomy)
- Diabetes mellitus(mechanism is usually vascular and neurogenic)
- Hypo or Hyperthyroidism
- Hyperprolactinemia(prolactin secreting tumour)
Trauma
- Pelvis Fracture
- Radical surgery in the pelvis
- Radiotherapy of the pelvis
History and Physical examination
Onset sudden or gradual?
Sudden - psychogenic
Presence of early morning erections?
Yes - psychogenic
Is problem present only sometimes?
Yes - psychogenic
Only duration of erection that is inadequate.
Yes - vascular cause
As well as premature ejaculation?
Yes - psychogenic
Erections not often enough?
Yes - psychogenic
Loss of libido/depression?
Yes - low testosterone
Symptoms of anxiety, fear, depression?
Yes - psychogenic
Chronic diseases, previous surgery, or trauma?
Current medications, smoke, alcohol, drugs?
NB: Treatment
Oral PDE-5 inhibitors (Viagra, Levitra, Cialis) have revolutionized treatment
Other options:
Psychotherapy
Testosterone supplementation
Intra-ureteral alprostadil
Intra-cavernous injections
Vacuum device
Penile prosthesis
NB: Oral PDE-5 inhibitors -
Key treatment esp. non-neurogenic causes
Physiology of normal erection and the role of PDE- inhibitors
Physiology of Normal Erection:
- Nitric Oxide (NO): During sexual stimulation, nitric oxide is released in the corpus cavernosum of the penis.
- cGMP Production: NO activates the enzyme guanylate cyclase, which increases levels of cyclic guanosine monophosphate (cGMP).
- Smooth Muscle Relaxation: cGMP causes the smooth muscle in the corpus cavernosum to relax, allowing blood to flow in and create an erection.
Role of PDE-5 Inhibitors:
- Inhibition of PDE-5: PDE-5 is an enzyme that breaks down cGMP.
- By inhibiting PDE-5, these medications increase cGMP levels, enhancing and prolonging the erection.
Types of PDE-5 Inhibitors
- Sildenafil (Viagra): Often taken about an hour before sexual activity, effective for 4-6 hours.
- Tadalafil (Cialis): Known for its longer duration of action, up to 36 hours, and can be taken daily at lower doses.
- Vardenafil (Levitra): Similar to sildenafil, but may have a slightly longer duration of action.
Instructions on usage of PDE-5 Inhibitors
- Use 1-2 hours prior to sex
- Use on empty stomach (fatty meals affect absorption)
- Normal stimulation still required to initiate erection,
- Detumescence to be expected after ejaculation
Contra-indications of PDE-5 Inhibitors
- Unstable angina
- Nitrate use
- MI in last 6 weeks
- Retinitis pigmentosa
NB slide: Other Erectile Dysfunction treatment options
- Intr-urethral
- Vacuum device
- Intracavernous injection
Intra-urethral
- MUSE – Medicated Urethral System for Erection
- Alprostadil pellet
- Penile pain is a common S/E
Not routinely available in SA
Vacuum device
- Plastic cylinder + vac generating source
- Negative pressure engorges penis, then constriction ring at base prevents detumescence – not for > 30 min
Cost effective solution
Intracavernous injection (ICI)
- Small amount of vasodilator injected into cavernosum
- Papaverine
- Phentolamine (α-blocker)
- Alprostadil (PGE1)
- “Trimix”
- 1st line treatment for neurogenic ED & C/I to PDE5-inh
Moderately higher risk for priapism compared to other Rx
Erectile dysfunction: List 2 Surgical interventions
- Penile revascularization
- Penile prosthesis (commonly used)
Explain the 2 surgical interventions above
Table in the mock exam
1. Penile revascularization:
- Inferior epigastric artery
- Penile prosthesis:
- 2nd or 3rd line treatment for ED: Malleable / inflatable options
- Very high patient and partner satisfaction rate – normal sensation and orgasm
- Complications: Erosion / Infection of prosthesis
