Transcript Anatomy and Physiology of erection

Erectile Dysfunction
John Ewan
Sandyford
Glasgow
Overview
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Epidemiology
Anatomy and Physiology
History
Examination
Investigations
Treatment
Definition of ED
DSM-IV (American Psychiatric Association, 2000)
 Persistent or recurrent inability to attain, or to
maintain until completion of the sexual activity, an
adequate erection
 The disturbance causes marked distress or
interpersonal difficulty
 The erectile dysfunction is not better accounted for
by another Axis I disorder (other than a sexual
dysfunction) and is not due exclusively to the direct
physiological effects of a substance (e.g. a drug of
abuse, a medication) or a general medical condition
Epidemiology
Massachusetts Male Aging Study, Feldman et al. J Urol 1994; 150:54-61
Reproduced from Carson C,Holmes S,Kirby R. Fast Facts-Erectile Dysfunction. Oxford: Health Press Limited; 2002 : 7
Anatomy and Physiology of erection
Reproduced from Carson C, Holmes S, Kirby R. Fast Facts- Erectile Dysfunction. Oxford: Health Press Limited; 2002: 8
Anatomy and Physiology of erection
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Parasympathetic nerves S2-4 mediate erection
Sympathetic nerves T11-L2 control ejaculation and
detumescence
Smooth muscle relaxation
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Nitric oxide diffuses into cavernosal smooth muscle cells,
activates Guanylate cyclase converts guanosine
triphosphate to cGMP resulting in smooth muscle relaxation.
Effect of cGMP stopped by Phosphodiesterase type 5 which
exists primarily in corpora cavernosa.
Veno-occlusive Mechanism
Reproduced from Carson C,Holmes S,Kirby R. Fast Facts-Erectile Dysfunction. Oxford: Health Press Limited; 2002 :12
History
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Detailed description of problem, is it ED?
Causative factors
Sexual desire/libido
Ejaculatory disorders
Impact on quality of life and on relationship
Expectations of treatment
Clues differentiating psychogenic from
organic causes
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Psychogenic
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Sudden onset
Situational
Normal waking and
nocturnal erections
Normal erection with
masturbation
Relationship problems
Life event
Anxiety, fear, depression
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Organic
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Gradual onset
All situations
Reduced or absent
waking and nocturnal
erections
No erection with
masturbation
Penile pain
Relationship issues
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Current relationship status
Length of relationship
Previous sexual partners and relationships
Partner issues e.g. menopause/pain/cancer
History
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Medical
Surgical
Psychiatric
Medication
Smoking
Alcohol
Recreational drug use
Arteriogenic Cause of ED
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Hypertension
Smoking
Diabetes
Hyperlipidaemia
Peripheral vascular disease
Blunt perineal or pelvic trauma
Pelvic irradiation
Neurogenic causes of ED
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Lesions of medial preoptic nucleus, paraventicular nucleus,
hippocampus
Spinal trauma
Myelodisplasia (spina bifida)
Pelvic surgery/radiotherapy
Multiple sclerosis
Intervertebral disc lesion
Peripheral neuropathies
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Alcohol
Diabetes
HIV
Psychogenic and Psychiatric causes
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Anxiety
Loss of attraction to partner
Relationship difficulties
Stress
Depression
Psychogenic ED
Reproduced from Carson C,Holmes S,Kirby R. Fast Facts-Erectile Dysfunction. Oxford: Health Press Limited; 2002 : 33
Endocrine causes of ED
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Hypogonadism
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Low testosterone
Raised SHBG
Raised Prolactin
Thyroid disease
Drugs associated with ED
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Antihypertensives
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Antidepressants
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Thiazides
B blockers
Centrally acting drugs
Tricyclics
MAO inhibitors
SSRI
Anticholinergics
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Atropine
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Antipsychotics
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Anxiolytics
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Phenothiazines
Benzodiazepines
Psychotropic drugs
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Alcohol
Opiates
Amphetamines
Cocaine
Examination
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Blood pressure
Peripheral pulses, palpate for AAA
Testes size and consistency
Secondary sexual characteristics
Penis for Peyronie’s plaques, phimosis
ED and Coronary Artery Disease
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Generalised atherosclerosis
Penile arteries smaller than coronary arteries
ED pre-dates coronary artery disease
Man with ED and no cardiac symptoms is a
cardiac patient until proven otherwise
Investigations
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Fasting glucose and lipids
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Morning testosterone and SHBG
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If testosterone is low or borderline repeat
with Prolactin, FSH and LH
Thyroid function
PSA
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Specialised Investigations
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Vascular studies
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Young patients with primary ED
History of trauma e.g. penile fracture
Patients unresponsive to medical therapies
Treatment of ED General Measures
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Smoking cessation
Reduce alcohol
Weight loss
Exercise
Endocrine Disorders
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Hypogonadism
Hyperthyroidism
Hyperprolactinaemia
Endocrinology referral
Psychosexual therapy
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Even if cause of ED is physical the patient
will develop psychosexual issues
Performance anxiety
Sensate focus exercises
Relationship counselling
Drugs for ED
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Oral agents
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Intra-cavernosal
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Centrally acting dopamine-receptor agonist
Apomorphine (discontinued in UK)
Phosphodiesterase type 5 inhibitors
Prostaglandin E1 Alprostadil
Intra-urethral
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Alprostadil
PDE5 inhibitors
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Sildenafil (Viagra) 25mg, 50mg, 100mg
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Tadalafil (Cialis) 10mg, 20mg
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30 minutes before sexual activity
36 hour window
Absorption not affected by food
Tadalafil (Cialis) 5mg
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1 hour before sexual activity
4-6 hour window
Absorption delayed by fatty meal
daily
Vardenafil (Levitra) 5mg, 10mg, 20mg
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30-60 minutes before sexual activity
4-6 hour window
Absorption delayed by fatty meal
PDE5 Physiology
Reproduced from Carson C,Holmes S,Kirby R. Fast Facts-Erectile Dysfunction. Oxford: Health Press Limited; 2002 : 40
PDE5 Inhibitors Side Effects
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Facial flushing
Headache
Nasal congestion
Dizziness
Dyspepsia
Visual disturbance (blue halo)
Priapism
Non-arteritic anterior ischaemic optic neuropathy
PDE5 Contraindications
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Recent cardiovascular event
Nitrates
Hypotension
Anatomical deformity
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Angulation, cavernosal fibrosis, Peyronie’s
Predisposition to prolonged erection
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Sickle cell disease
Multiple myeloma
Leukaemia
PDE5 Drug Interactions
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Nitrates
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Cytochrome P450 inhibitors
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Glyceryl trinitrate, isosorbide mono or dinitrate
Chest pain after taking Sildenafil/Vardenafil no nitrates 24
hours, Tadalafil no nitrates 48 hours
Recreational amyl nitrate (Poppers)
Protease inhibitors especially Ritonavir use very small dose
Cimetidine, Ketoconazole, Erythromycin
Alpha blockers
Intracavernosal Injections
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Alprostadil (Caverject, Viridal) 5-40 mcg
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Independent of intact nervous system
Manual dexterity, adequate vision, training
Contraindicated: bleeding disorders, sickle cell anaemia,
multiple myeloma, leukaemia
Side effects: penoscrotal pain, haematoma, fibrosis at
injection sites, priapism
Papaverine, Phentolamine, Aviptadil (vaso-intestinal
peptide) been used sole or with Alprostadil
Intracavernosal Injections
Reproduced from Carson C,Holmes S,Kirby R. Fast Facts-Erectile Dysfunction. Oxford: Health Press Limited; 2002 : 53
Intraurethral
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Alprostadil (Muse) 125mg, 250mg, 500mg,1g
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Pellet inserted with applicator
Massage penis to aid absorption
Side effects: Penile pain, dizziness, priapism rare
Intraurethral Alprostadil
Reproduced from Carson C,Holmes S,Kirby R. Fast Facts-Erectile Dysfunction. Oxford: Health Press Limited; 2002 : 55
Vacuum Devices
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Blood trapped in intracorporal and
extracorporal compartments of penis
Constricting ring at base of penis
Cyanosis, oedema, cold
Pivots at base below ring
Maximum time 30 minutes
Vacuum devices
Reproduced from Carson C,Holmes S,Kirby R. Fast Facts-Erectile Dysfunction. Oxford: Health Press Limited; 2002 : 61
Penile Prostheses
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Semi-rigid rods
2 piece inflatable prosthesis
3 piece inflatable prosthesis with abdominal reservoir
Risks
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Infection
Destroys corpora cavernosa
Erosion and extrusion
Mechanical failure
Penile Prosthesis
Reproduced from Carson C,Holmes S,Kirby R. Fast Facts-Erectile Dysfunction. Oxford: Health Press Limited; 2002 : 66
NHS Prescription for ED
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Diabetes
Multiple sclerosis
Parkinson’s Disease
Poliomyelitis
Prostate cancer
Prostatectomy incl TRP
Radical pelvic surgery
Severe pelvic injury
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Renal failure
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On dialysis
Transplant
Single gene neurological
disease
Spinal cord injury
Spina bifida
Receiving NHS Rx
14/9/1998
Severe distress
Private Prescription
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Pharmacy costs vary
Sildenafil 100mgX4 £25-£40
Pharmacy2U £25
Conclusions
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ED is a common problem
Impact on patient and partner/s
Overlap of psychological and physical
May be initial presentation of diabetes or
coronary artery disease
Good range of safe and effective therapies
If YOU don’t ask your patient may be too
embarrassed to tell you