1. Dr Saqib Mahmud MRCP(UK), MRCPS(Glasg), MRCGPED
Dr Saqib Mahmud
MRCP(UK), MRCPS(Glasg), MRCGP

2. Incidence- increase with age 39% men aged 40yrs, 67% age 70yrs
ED-inability to achieve/maintain an erection sufficient for mutually satisfying intercourse
Incidence- increase with age
39% men aged 40yrs, 67% age 70yrs
Present worldwide prevalence>150 million men, double in next 25yrs >300 million men by 2025
Previously thought of inorganic origin, now believed that ED is increasingly due to organic disease

3. Mechanism of erection Largely a vascular event
In response to sexual stimuli, parasympathetic nervous system dilates cavernosal arteries & relaxes trabecular smooth muscle increased blood flow filing sinusoidal spaces engorge penis (tumescence) compress & stops venous outflow maintaining the erection
Reverse of these events after ejaculation sympathetic activity--.contraction of arteries & trabecular smooth muscle--.venous outflow decompression of venous channels (detumescence)

4. Chemical pathways in penile erection
Most important NO-induced cGMP pathway
Endothelial cells release NO in response to sexual stimuli
NO increases cGMP, which relaxes the corpus cavernosal smooth muscle leading to an erection
Detumescence occurs when cGMP is broken down by an enzyme ‘’phosphodiesterase’’(PDE-5)hence the role of PDE5 inhibitors in maintaining the erection

5. causes
Vascular-endothelial dysfunction, atherosclerosis, htn, hypercholesterolemia
Endocrine-DM, hypothyroidism, hyperprolactinaemia, testosterone deficiency, hormonal imbalance due to hepatic & renal disease
Neurological-MS, CVA, Parkinson’s, Alzheimer’s, spinal cord & brain injuries
Peyronie’s disease- rare inflammatory condition->scaring of erectile tissue->painful erection

6. Drugs->200 commonly prescribed drugs can cause or contribute to ED
Beta-blockers
Diuretics-BFZ, furosemide
ACEI
CCB
LH-RH analogs
Antiandrogens
Benzodiazepines
Alcohol
Illicit drugs

7. Other causes of ED Pelvic trauma Radiotherapy
Colorectal, prostate & bladder surgery increases the risk of ED
Vascular leak- veins unable to constrict efficiently during erection
Substance abuse- chronic use of cocaine, marijuana, alcohol, steroids
Excessive use of tobacco-nicotine in tobacco causes contraction of small blood vessels less flow to the region->ED

8. Psychological causes of ED
Depression
Anxiety
Stress
Performance anxiety– anxiety & stress lead to increased production of catecholamine which act as erection inhibitors

9. Assessment – ED as a marker
Study of 980 men with ED found;
18% - undiagnosed HTN
16% - DM
15% - BPH
5% - IHD
4% - Ca Prostate
1% - Depression
b/w 39 & 64% of males with CVD suffer from ED

10. Physical Assessment BP
Femoral & peripheral pulses, femoral bruits – vascular abnormalities / PVD
Neurological exam – deep tendon reflexes, bulbocavernosis reflex (gentle squeeze of glans anal contraction), reduced sensation- sacrum, perineum
Visual field defects – prolactinoma, pituitary mass
Gynaecomastia – hyperprolactinaemia
Testicular atrophy- testosterone def, hypogonadism

11. Assessment - contd
Rectal exam – assessment of prostate & sphincter tone
PHQ-9 Questionnaire
FBS
U&Es, LFTs, TFTs
Serum testosterone & SHBG, prolactin

12. Management of ED PDE5 inhibitors – sildenafil, tadalafil, vardenafil
Sildenafil (1998) - 25mg, 50mg,100mg
Taken 1hr before sex, effective up to 4 to 5 hrs, s/e - headache
Tadalafil (2003) – 10mg, 20mg(PRN) 2.5mg, 5mg(once daily-2009)
Taken 30 minutes before sex, effective up to 36hrs, s/e - dyspepsia, headache

13. contd Vardenafil(2003) – 5mg, 10mg, 20mg
Taken 25 – 60minutes before sex, effective up to 4 – 5 hrs, s/e – headache, flushing

14. When PDE5 inhibitors don’t work
Patient Education
81% do not take them correctly
Adequate sexual stimulation necessary
Food & alcohol delay & reduce absorption
Some need 6-8 doses before an optimal response occurs
Psychotherapy integrated with pharmacotherapy

15. Prescribing advice Switch drugs Optimize dose – increase to max
Patients unresponsive to PRN Tadalafil, consider once daily regime
Combine with other drugs; intraurethral alprostadil with PDE5 inhibitors or with doxazocin (weak erectogenic agent) ideal with BPH+HTN patients

16. Other treatments for ED
MUSE – medicated urethral system for erection, pallet of PGE1(alprostadil) inserted in urethra 15min before sex, lasts 30 to 60min
Can be used up to twice daily
s/e – penile pain, burning (32%)
43% efficacy compared to intracavernosal route but less complications such as priapism and penile fibrosis with injections

17. Vacuum constriction devices
SOMACorrect Xtra, SOMAerect Response II
One time cost (£160 - £180/-)
Efficacy – 92% regardless of underlying cause of ED
Time to erection onset- 90 to 120 seconds
Time required to terminate erectin <30seconds
No systemic side effects compared to oral Rx

18. Surgical treatment for ED
Penile prosthesis – for patients who probabaly have sufffered physical damage to corpora, renndering other treatments ineffective
Vascular surgery – when ED is due to poor arterial inflow or abnormal venous drainage ( arterial revascularization, ligation of venous incompetence)
Results vary widely but usually poor

19. Testosterone therapy
Only indicated in men whose loss of libido/ ED is due to hypogonadism or documented low testosterone levels
Testosterone deficiency is a rare cause of ED
Administered orally, i/m injections, skin patches or implants