Makindo Medical Notes

🍆 Erectile Dysfunction (ED) = persistent inability to achieve or maintain an erection sufficient for satisfactory sexual performance. It is common, impacts quality of life, and is often an early marker of systemic vascular disease.

📖 Definition

• ED = difficulty obtaining or maintaining an erection until completion of sexual activity, present ≥3 months.
• Differentiate from decreased libido 🔽, ejaculatory disorders 💦, and infertility 🧬.

🧬 Physiology & Pathophysiology

• Normal erection requires:
  • 🧠 Neural input: Parasympathetic S2–S4 → nitric oxide → smooth muscle relaxation.
  • 🩸 Vascular inflow: Cavernosal artery dilation → ↑ blood filling.
  • 🚧 Venous occlusion: Blood trapped within corpora cavernosa.
  • 💪 Hormones: Adequate testosterone.
• ED results from disruption in one or more: vascular (HTN, atherosclerosis), neurogenic (SCI, neuropathy), endocrine (hypogonadism, diabetes), psychogenic (anxiety, depression).

⚠️ Causes of ED

Category	Examples
🧠 Psychogenic	Stress, performance anxiety, depression
🩸 Vascular	HTN, atherosclerosis, diabetes, smoking
🧬 Neurological	MS, spinal cord injury, peripheral neuropathy
💉 Endocrine	Hypogonadism, diabetes, thyroid disease
💊 Drugs	SSRIs, TCAs, β-blockers, alcohol, cannabis, cocaine
🔀 Mixed	Combination is very common

🩺 Clinical Assessment

• 📖 History: Onset (sudden = psychogenic, gradual = organic), nocturnal erections (present = psychogenic), libido, systemic illness, psychiatric history, substance use.
• 👨‍⚕️ Exam: Secondary sexual characteristics, genital exam (Peyronie’s, testicular size), pulses/BP (vascular disease), neuro exam (neuropathy).

🔬 Investigations

• 🩸 Bloods: Fasting glucose/HbA1c, lipids, testosterone, prolactin, TFTs.
• ❤️ Cardiac risk assessment: ECG, exercise test if high vascular risk.
• 🖥️ Penile Doppler US: specialised, for surgical planning.

💊 Management

• 🌱 Lifestyle: Stop smoking 🚭, reduce alcohol 🍷, weight loss ⚖️, exercise 🏃.
• 🧠 Psychological: CBT, counselling, couples therapy.
• 💊 Pharmacological: PDE5 inhibitors (sildenafil, tadalafil, vardenafil) — enhance NO–cGMP pathway → erection. ❌ Contraindicated with nitrates → severe hypotension.
• 🛠️ Other therapies: Vacuum devices, intracavernosal alprostadil, intraurethral pellets, penile prosthesis (last-line).

📈 Prognosis

• Most men respond to PDE5 inhibitors or devices.
• Addressing lifestyle risks improves erectile & CV health.
• ⚡ ED can precede coronary artery disease by 2–5 years → treat as a vascular warning sign.

✨ Clinical Pearls

• 💡 Sudden ED + normal morning erections → psychogenic.
• ⚡ Gradual ED → organic (usually vascular).
• ❤️ “Angina of the penis” → ED as sentinel for systemic vascular disease.
• ❌ PDE5 inhibitors + nitrates = fatal hypotension.
• 🧑‍⚕️ Always check testosterone if libido low.

🧑‍⚕️ Case Examples

Case 1: 👨 A 52-year-old man with type 2 diabetes presents with gradual onset ED. He has reduced morning erections and mild peripheral neuropathy. 🧪 HbA1c 72 mmol/mol, fasting glucose elevated, testosterone normal. ✅ Management: optimise diabetes control, lifestyle changes, start PDE5 inhibitor, screen for cardiovascular risk.

Case 2: 👨 A 40-year-old man reports sudden onset ED after starting sertraline for depression. He still has normal nocturnal/masturbatory erections. 🔎 Exam and testosterone normal. ✅ Management: recognise drug-induced/psychogenic component, discuss alternative antidepressant, consider CBT, PDE5 inhibitor if needed.

📚 References

• NIDDK – Erectile Dysfunction
• Mayo Clinic – ED Overview
• AUA Guidelines – Urology Guidelines
• Feldman HA et al., JAMA 1994. Massachusetts Male Aging Study.
• McMahon CG. Lancet 2003. Erectile Dysfunction.
• Kim ED. Urology 2010. PDE5 Inhibitors.