Sexual Dysfunction¶
Chapter 409 | Part 12: Endocrinology and Metabolism
KEY CLINICAL POINTS¶
- Erectile dysfunction (ED) is a common disorder affecting 52% of men aged 40–70 and 43% of women, with significant impacts on quality of life.
- PDE-5 inhibitors (sildenafil, tadalafil, vardenafil, avanafil) are first-line treatments for ED, with tadalafil having the longest duration of action.
- Female sexual dysfunction (FSD) includes desire, arousal, orgasmic, and pain disorders, often linked to hormonal, vascular, and psychosocial factors.
1. DEFINITION & OVERVIEW¶
Sexual dysfunction encompasses disorders of libido, erection, ejaculation, orgasm, and sexual pain. It includes male sexual dysfunction (ED, premature ejaculation, retrograde ejaculation) and female sexual dysfunction (hypoactive sexual desire, arousal disorders, orgasmic disorders, sexual pain).
Table 409-1 Drugs Associated with Erectile Dysfunction¶
| CLASSIFICATION | DRUGS | POSSIBLE SUBSTITUTES |
|---|---|---|
| Diuretics | Thiazides | Spironolactone |
| Antihypertensives | Calcium channel blockers | a-Adrenergic blockers |
| Endocrinologic | Androgens | Spironolactone |
| Medication-Related | Selective serotonin reuptake inhibitors | Bupropion |
| Hormones | Progesterone | Estrogens |
1.1 Male Sexual Dysfunction¶
ED is defined as the persistent inability to achieve or maintain an erection sufficient for satisfactory sexual performance. Premature ejaculation is characterized by ejaculation within 1 minute of penetration, while retrograde ejaculation occurs when semen enters the bladder instead of exiting through the urethra.
1.2 Female Sexual Dysfunction¶
FSD includes chronic conditions in desire, arousal, orgasm, and pain domains. It is often associated with hormonal imbalances, vascular insufficiency, and psychosocial factors.
2. EPIDEMIOLOGY¶
ED affects 52% of men aged 40–70 (10% complete ED, 25% moderate ED). FSD prevalence is 43% in women, with higher rates in postmenopausal women. Risk factors include diabetes, cardiovascular disease, hypertension, and psychosocial stressors.
Table 409-4 Risk Factors for Female Sexual Dysfunction¶
| Category | Risk Factors |
|---|---|
| Neurologic Disease | Stroke, spinal cord injury, parkinsonism |
| Trauma/Surgery | Genital surgery, radiation |
| Endocrinopathies | Diabetes, hyperprolactinemia |
| Cardiovascular | Hypertension |
| Psychological | Sexual abuse, life stressors |
2.1 Male ED¶
Incidence doubles between ages 40–7, with 21% of men aged 50–59 reporting ED. Risk factors include diabetes, BPH, and cardiovascular disease.
2.2 Female FSD¶
43% of women report at least one sexual problem. Hypertension, diabetes, and hormonal changes (e.g., menopause) are significant risk factors.
3. ETIOLOGY & PATHOPHYSIOLOGY¶
ED arises from three mechanisms: psychogenic (anxiety, depression), vascular (atherosclerosis, venous leak), and neurogenic (spinal cord injury). FSD is linked to hormonal imbalances, vascular insufficiency, and psychosocial factors.
3.1 Male ED Pathophysiology¶
Nitric oxide (NO) mediates penile erection via cyclic GMP. PDE-5 inhibitors enhance NO activity. Vascular causes include atherosclerosis, while neurogenic causes involve spinal cord injury.
3.2 Female FSD Pathophysiology¶
Estrogens and androgens synergistically enhance arousal. Vaginal lubrication depends on vascular engorgement. Hormonal imbalances, diabetes, and antidepressants contribute to dysfunction.
4. CLINICAL FEATURES¶
Male ED presents with erection failure, while FSD includes low libido, arousal difficulties, pain, or lack of orgasm. Psychogenic ED may coexist with anxiety or depression.
4.1 Male Symptoms¶
Erectile failure, premature ejaculation, retrograde ejaculation, and detumescence issues. Psychogenic ED may involve performance anxiety.
4.2 Female Symptoms¶
Low desire, arousal difficulties, dyspareunia, and orgasmic disorders. Vaginal dryness and pain are common in postmenopausal women.
5. DIFFERENTIAL DIAGNOSIS¶
For ED: diabetes, cardiovascular disease, neurological disorders, and medication side effects. For FSD: hormonal imbalances, antidepressants, and psychosocial factors.
5.1 Male ED¶
Diabetes, atherosclerosis, spinal cord injury, and medication use (e.g., SSRIs, alpha-blockers).
5.2 Female FSD¶
Hypothyroidism, hyperprolactinemia, antidepressants, and hormonal changes (e.g., menopause).
6. INVESTIGATIONS & DIAGNOSIS¶
Diagnostic tools include the IIEF questionnaire, SHIM, and physical exams. Laboratory tests assess testosterone, prolactin, and lipid profiles. Vascular testing (Doppler ultrasound) and nocturnal penile tumescence monitoring may be used.
6.1 Diagnostic Criteria¶
IIEF scores <21 indicate ED. SHIM scores <20 suggest moderate to severe dysfunction. Nocturnal penile tumescence testing confirms organic ED.
6.2 Laboratory Tests¶
Testosterone, prolactin, FSH/LH, and lipid profiles. Thyroid function tests and HbA1c for diabetes screening.
7. MANAGEMENT & TREATMENT¶
First-line therapies include PDE-5 inhibitors. Testosterone therapy, vacuum devices, and penile implants are alternatives. Hormonal replacement (estrogen) and lubricants address FSD. Psychological counseling and lifestyle modifications are critical.
Table 409-2 PDE-5 Inhibitors¶
| DRUG | ONSET OF ACTION | T½ | DOSE | ADVERSE EFFECTS | CONTRAINDIC ATIONS |
|---|---|---|---|---|---|
| Sildenafil | 30–120 min | 2–5 h | 25–100 mg | Headache, flushing | Nitrates, cardiovascular risk |
| Tadalafil | 30–60 min | 17.5 h | 10–20 mg | Headache, dyspepsia | Nitrates, heart failure |
| Vardenafil | 30–120 min | 4.5 h | 5–10 mg | Headache, rhinitis | Nitrates |
| Avanafil | 30 min | 3–5 h | 50–200 mg | Headache, nasal congestion | Nitrates |
7.1 Pharmacologic Treatments¶
PDE-5 inhibitors (sildenafil, tadalafil), testosterone replacement, and topical estrogen. Avoid nitrates and alpha-blockers with PDE-5is.
7.2 Non-Pharmacologic Approaches¶
Sex therapy, vacuum devices, and lifestyle changes (exercise, smoking cessation). Counseling for psychogenic ED.
8. PROGNOSIS & COMPLICATIONS¶
ED is a sentinel symptom for cardiovascular disease. Untreated FSD may lead to relationship strain and reduced quality of life. Complications include depression, anxiety, and sexual avoidance.
8.1 Cardiovascular Link¶
ED correlates with cardiovascular severity. PDE-5 inhibitors may reduce cardiovascular mortality.
8.2 Psychosocial Impact¶
FSD is associated with depression, relationship conflict, and reduced sexual satisfaction.
9. SPECIAL CONSIDERATIONS¶
Pregnancy: Avoid PDE-5is. Pediatrics: ED in adolescents may indicate underlying disease. Elderly: Monitor for cardiovascular risks. Hormonal therapy requires careful dosing in women.
9.1 Pregnancy¶
Avoid PDE-5 inhibitors. FSD in pregnancy may be due to hormonal changes or stress.
9.2 Elderly Patients¶
Higher risk of cardiovascular comorbidities. Adjust dosages for PDE-5is and monitor for hypotension.
10. KEY POINTS & CLINICAL PEARLS¶
- PDE-5 inhibitors are first-line for ED, with tadalafil having the longest duration. 2. FSD is often multifactorial, requiring hormonal, psychological, and lifestyle interventions. 3. Testosterone therapy improves ED in hypogonadal men but is contraindicated in those with prostate cancer. 4. Regular follow-up is essential to monitor for cardiovascular risks and treatment efficacy.