Sexual dysfunction in Men (ED)

Question 1

Background

Answer 1

ED = the persistent inability to attain and maintain an erection sufficient to permit satisfactory sexual performance.
Types of dysfunction in men:
- Decreases libido (self explanatory)
- Increased libido (self explanatory)
- ED (impotence) = ED definition above
- Delayed ejaculation = Dry sex - delayed or absent ejaculation
- Retrograde ejaculation = Passes backwards in to bladder
- Infertility = Sperm insufficient number, abnormal morphology, inadequate motility, failure to fertilise egg.

Question 2

Causes / Risk factors

Answer 2

ED is a symptom

Risk factors:
- Obesity (lack of exercise, sedentary life)
- Smoking and alcohol
- Bike riding >3hours a week
- CVD (angina etc)
- HTN
- Dyslipidaemia
- Metabolic syndrome
- Obstructive sleep apnoea (stop breathing)
- BPH

Causes
* Vascular: HTN, atherosclerosis, hyperlipidaemia, smoking
* Neurological: PD, multiple sclerosis, stroke, spinal cord injury, peripheral neuropathy
* Hormonal: hypogonadism, hyperprolactinaemia, thyroid disease, Cushing’s disease
* Drug-induced: antihypertensives, (beta-blockers, diuretics, verapamil, methyldopa, clonidine) antidepressants (TCA, MOAi, SSRi, lithium, venlafaxine), antipsychotics (Chlorpromazine, haloperidol, phenothiazines), AED (Carbamazepine, topiramate, gabapentin, pregabalin), recreational drugs
* Systemic disease: DM, renal failure
* Structural: pelvic trauma, penile trauma, Peyronie’s disease
* Psychogenic (general or situational)

Question 3

Assessment and Diagnosis

Answer 3

Assessment:
Look for underlying cause. Ask about
- Psychosexual factors (sexual orientation, sexual function, religious beliefs, life events)
- Medical Hx
- Perform physical exam: Measure BP, HR, Waist circumference, BMI.
Look for gynaecomastia, sparse body hair, reduced muscle mass for Testosterone deficiency. Exam external genitalia - structure, foreskin conditions. Can do Digital rectal exam to check prostate.
- Arrange blood test to check underlying cause and CV risk: HbA1c, Serum lipid profile, Fasting serum T levels.

Question 4

Treatment

Answer 4

Combo of DRUG + Lifestyle changes (including regular exercise, reduction in BMI, Smoking cessation, reduced alcohol)

DRUG:
1st line oral phosphodiesterase type-5 inhibitor = Avanafil, sildenafil (OTC) and vardenafil (all short term), Tadalafil (long term)

2nd line Alprostadil (prostaglandin E1) Intracavernosal, intraurethral, topical forms. Taken under supervision.

MOA:
PDE 5 i - cGMP activates protein kinase G = vasodilation in penile artries = erection. PDE 5 degrades cGMP to GMP. PDE 5 i prevent degrading and allows more cGMP = vasodilation = Erection.

PG E1 - Makes cAMP = vasoldilation and muscle relaction. = applied locally to penis = erection

Question 5

Counselling on drugs

Answer 5

5 PDE: CHECK THIS
Follow up 6 – 8 weeks after.
- Contraindicated: recent stroke, ACS, or significant CVD. Avoid in Low BP
Avoided or lower dose used in severe renal/ hepatic impairment due to reduced metabolism and excretion.
- Interactions:
Drugs that increase NO (nitric oxide) - nitrates/ nicorandil.
Caution - vasodilators (alpha blocker - sepearte doses by 4 hrs, CCB)
Plasma CONC. and AE risk increased by CYP450i (eg amiodarone, diltiazem, fluconazole)
Get Medical advise if erection dont stop 2 hrs after sex.

S- Onset delayed when taken with food, Take 1 hr b4 sex, only 50mg OD.

Refer if fail to respond to 2 different PDE 5 and max 6 doses.

Alprostadil: (PG E1)
Ureteral or topical forms:
- U - Max 2/day & 7/week.
- T - Max 1/day & 2-3/ week
15–30 min b4 sex. Medical attention if erect >4hrs (priapism)

U - Condom if partner pregnant
T- Condom use to avoid exposing P, BF or child bearing age women to drug.

Explain how to apply cream.
Intracavernosal 1st dose by specialist. after training then can self administer

Priapism Alprostadil treatment:
- Ice pack to upper thighs alternate between thighs every 2 min for 10 min.
- Initial penile aspiration 20-50mL blood.
- Lavage - saline injected then drained.
- Intracavernosal injection of a sympathomimetic
- ALL above fail in order = URGENY REFER

Question 6

Anatomy (extra)

Answer 6

• 3 bodies erectile tissue - right and left corpus cavernosa and central corpus spongiosum. They fill with blood when aroused.
• 4 muscles - they maintain erection and empty urethra - 2 bulbospongiosus + 2 ischiocavernosus
• 3 layers that cover the above: , Dartos fascia, Buck’s fascia and Tunica albuginea - protect above.
• Blood supply via dorsal penile artery, the deep penile artery and the bulbourethral artery - all come from internal pudendal artery.
• Blood drained via superficial and deep dorsal veins to the superficial external pudendal vein and prostatic venous plexus