Erectile dysfunction is a growing problem that affects over 150 million men worldwide. It is caused by various vascular, neurological, endocrine, psychological, and pharmacological factors that can impair blood flow or nerve signaling in the penis. Common medical treatments include phosphodiesterase type 5 inhibitors like sildenafil (Viagra), which help maintain blood flow; penile injections; vacuum devices; testosterone replacement therapy; and penile implants. Counseling may also help address psychological aspects.

1. Erectile dysfunction – a growing problem Erection Physics

6. Sequence of events Stimulus Either cerebral cortex or tactile

7. Visual Auditory Imagined tactile

8. Penile artery relaxation due to NO release in muscle cells Passive engorgement of pudendal arteries

9. Corpus cavernosa ( 2 main tubes in penis) corpus spongiosum These engorge Blood pressure strains on sheath Closes vein escape of blood

10. Blood and nerve function Blood and nerve supply in perineal area: Affected by injury (spinal cord) pressure plaque ( diabetes and CVD) medication ( also marijuana) smoking drugs (alcohol)

11. Other causes Age ( nerve function, diabetes, proper NO function, testosterone deficiency) Hypertension High estrogens Prostate cancer treatment ( surgery or hormonal) Transmitter problems

12. Erectile Dysfunction (ED) Definition Epidemiology Aetiology Clinical features History Examination Investigation Treatment

13. Definition The consistent inability to obtain and maintain penile erection sufficient to complete satisfactory sexual performance

14. definitions ED. Impotence Infertility

17. Basic Penis biology 3 types of cells in penile corpora cavernosa: Neuron cells release Nitric Oxide which causes calcium ions to enter storage areas and decrease calcium levels in tissue Then smooth muscles relax and endothelial cells flatten and block exodus of blood

18. Stimuli--  hypothalamus  autonomic nerves--  NO--  penile muscle relaxation  endothelial cells flatten on sides of sinusoids, block veins. Other neurotransmitters, like norepinephrine Increase calcium which contracts muscle cells Testosterone and acetylcholine also influence erection.

19. Summary: Messages via autonomic, cholinergic, norepinephrine and “T” control Nitric Oxide levels-  Calcium levels Autonomic nerve fibers  NO  enzyme (Guanylyl cyclase) -  converts cGTP into cGMP  calcium storage  sliding filament relaxation and sinusoids fill

20. treatments Penile injections ( smooth muscle relaxants) Converts cGTP to cGMP  Calcium levels  relaxed sinusoids Viagra and other ED meds. Inhibit cGMP degradation ( maintains erection) Phosphodiesterase 5 is the chemical which degrades cGMP…ending the erection

21. Name a famous drug? A phosphodiesterase type 5 inhibitor, often shortened to PDE5 inhibitor, is a drug used to block the degradative action of phosphodiesterase type 5 on cyclic GMP in the smooth muscle cells lining the blood vessels supplying the corpus cavernosum of the penis. These drugs are used in the treatment of erectile dysfunction, and were the first effective oral treatment available for the condition

22. Does Viagra need an intact apparatus? Needs penile blood flow Intact nerves and sensory impulses NO production Sexual stimulation

26. Epidemiology Estimated to affect 152m men worldwide Non-diabetic men 0.1-18.4% prevalence In a study of 541 diabetic males 35% in diabetic men 5.7% in 20-24 year olds 52.4% in 55-59 years olds ED is a growing problem Massachusetts Male Aging Study estimate an 11% world increase by 2015

27. Aetiology Vascular Neurological Endocrine Psychological Pharmacological Penile tissue abnormalities Others

28. Vascular Arterial insufficiency Endothelial dysfunction (up to 95%) Discrete lesions Venous leakage Failure of venule constriction

29. Neurological Damage to autonomic nervous system Predominant parasympathetic damage

30. Endocrine Hypogonadism Most commonly primary testosterone deficiency Secondary hypogonadism Hypothyroidism Hyperprolactinaemia

31. Other causes of ED Penile Balinitis Phymosis Penile finrosis Tumours Trauma Pharmacoloical

32. PMH Glycaemic control Vascular/neurological disease Urological PSH and trauma DH Anti-hypertensives Androgen antagonists Sedatives Drugs that cause hyperprolactinaemia (phenolthiazides) Alcohol Psychological assessment

33. Oral therapies Phosphodiesterase V inhibitors Sildenafl ( Viagra) 4hr Tadalafil ( Cialis) 17hrs Vardenafil (Levita) 4 hrs Side effects flushing, headache and GI disturbance Contraindications - nitrates

37. Efficacy of PDE-V inhibitors Hundreds of studies internauinally Improved erections and increased successful episodes of sexual intercourse vs placebo (15 RCTs)

38. PDE V inhibitor prescribing Following conditions DM PD, MS, polyiomyelitis Pinal cord injuries, spina bifida Radical prostatectomy

39. Vacuum devices Can improve erection Messy and user dependent Satisfaction varies 35-80%

40. Intracavernosal injections Intracavernosal injections with prostaglandins Alprostadil (prostaglandin E1) One large RCT found increased rate of satisfactory erections when alprostadil injected compared to placebo Side effects – pain, priapism

41. Testosterone replacement Improves erectile function and libido Preparations Topical (testim gel) Im testosterone Long-acting depots

42. Penile implant Inflatable Malleable

43. Psychosexual counselling Talking therapies for men and couples

44. Summary ED Common Marker for other forms of neurovascular complications in diabetes Psychologically damaging Treatable Treat associated hormonal deficiencies