chapter 69 Evaluation and Management of Erectile Dysfunction

Question 1

Best predictor for developing ED?

Answer 1

A: Passive cigarette smoke exposure
📝 Risk factors: age, smoking (active/passive), obesity, lower education, CVD, diabetes

Question 2

: ED and cardiovascular risk — what’s the relationship?

Answer 2

Bidirectional; ED predicts and is predicted by CVD
📝 ED is a “sentinel marker” of CVD risk

Question 3

What’s needed before lifestyle modification in ED?

Answer 3

Applies to all ED patients regardless of CVD risk level

Question 4

Q5: Key feature of organic ED (vs. psychogenic)?

Answer 4

A: Gradual decline in erectile ability
📝 Organic = gradual, global dysfunction, poor morning erectio

Question 5

: Main use of ED questionnaires (e.g., IIEF)?

Answer 5

Document responsiveness to treatment
📝 Not diagnostic or etiologic

Question 6

Best reason to use specialized diagnostic tests?

Answer 6

A: To assess complex ED presentations
📝 Not routinely needed; use when considering surgery or unexplained ED

Question 7

: When is penile duplex ultrasound reliable?

Answer 7

When combined with pharmacostimulation
📝 Allows accurate assessment of penile hemodynamics

Question 8

Test required before penile revascularization surgery?

Answer 8

A: Penile angiography
📝 Maps internal pudendal and penile arteries

Question 9

0: High SHBG leads to?

Answer 9

A: Lower bioavailable testosterone
📝 Free and albumin-bound testosterone are active forms

Question 10

Q11: How to judge testosterone therapy efficacy?

Answer 10

A: Symptomatic improvement of hypogonadism
📝 Labs help but symptoms are primary guide

Question 11

Molecular action promoting erection?
🟨 A: Cyclic nucleotides (cGMP, cAMP)

Answer 11

cGMP → smooth muscle relaxation → erection

Question 12

Contraindication to intracavernosal injection?

Answer 12

A: History of priapism
📝 Also avoid in unstable cardiac disease, severe coagulopathy

Question 13

Q14: Advantage of alprostadil for ICI?

Answer 13

A: Lower incidence of prolonged erection
📝 But more painful than other agents

Question 14

Q15: Vacuum erection device is most helpful for?

Answer 14

A: Glanular insufficiency
📝 Engorges entire penis, including glans

Question 15

Lesion corrected by penile revascularization?

Answer 15

A: Internal pudendal artery stenosis
📝 Best candidates: young, healthy, traumatic cause

Question 16

What is the NIH definition of erectile dysfunction (ED)?

Answer 16

A: Inability to attain or maintain an erection sufficient for satisfactory sexual performance.

📌 Board Pearl:

ED is defined by function, not frequency or penetration.

Always consider psychosocial impact when assessing severity

Question 17

What condition is most strongly associated with ED (highest odds ratio)?

Answer 17

A: Diabetes mellitus (OR ~2.9)

📌 Board Pearls (Other Odds Ratios):

Antidepressant use (SSRIs): OR ~9.1

Antihypertensives: OR ~4.0

Obstructive LUTS: OR ~2.2

BPH: OR ~1.9

Cardiovascular disease: OR ~1.6

Smoking: OR ~1.5

Question 18

What clinical tool is used to assess CV risk in men with ED?

Answer 18

Princeton Consensus Guidelines (low/intermediate/high risk stratification

Question 19

What percentage of men with ED actually receive treatment?

Answer 19

A: ~30%

📌 Board Pearl:

Underdiagnosed and undertreated despite high prevalence.

Men often avoid care due to stigma, embarrassment, or misinformation.

Question 20

What is the first-line vascular test for evaluating erectile dysfunction?

Answer 20

A: Penile duplex ultrasonography with pharmacostimulation
💡 Board Pearl: Noninvasive and most commonly used; evaluates both arterial inflow and veno-occlusion.

Question 21

What medication is used to induce an erection during penile duplex ultrasound?

Answer 21

Alprostadil (PGE1)
💡 Board Pearl: Pharmacostimulation is essential; testing without it is not diagnostic.

Question 22

What is a normal Peak Systolic Velocity (PSV) during duplex ultrasound?

Answer 22

A: ≥35 cm/s
💡 Board Pearl: PSV <25 cm/s = arteriogenic ED (insufficient arterial inflow

Question 23

What EDV value indicates venous leak during duplex US?

Answer 23

EDV >5 cm/s
💡 Board Pearl: Persistent diastolic flow = failure to trap blood → venous leak (veno-occlusive dysfunction).

Question 24

What is the formula for calculating Resistance Index (RI)?

Answer 24

A: (PSV – EDV) / PSV
💡 Board Pearl: RI reflects how well the penis resists venous outflow — a critical measure for diagnosing venous leak.

Question 25

Normal RI on penile duplex

Answer 25

A: RI ≥ 0.9 💡 Board Pearl: RI < 0.75 = abnormal, indicating possible veno-occlusive dysfunction.

Question 26

What is the gold standard test for diagnosing venous leak?

Answer 26

DICC (Dynamic Infusion Cavernosometry and Cavernosography) 💡 Board Pearl: DICC directly measures intracavernosal pressure and leak location, but is invasive.

Question 27

When is penile angiography indicated?

Answer 27

🟨 A: When considering penile revascularization surgery Board Pearl: Only appropriate in young men with focal arterial lesions and normal venous function.

Question 28

What finding during DICC confirms venous leak?

Answer 28

A: Low intracavernosal pressure with rapid contrast washout 💡 Board Pearl: Identifies failure to trap blood — useful for surgical planning.

Question 29

Which vascular ED test is no longer recommended due to poor accuracy?

Answer 29

A: Penile-Brachial Index (PBI) 💡 Board Pearl: Replaced by duplex US — PBI has low sensitivity and specificity for ED causes.

Question 30

What does NPT testing evaluate?

Answer 30

A: Nocturnal penile erections during REM sleep to distinguish organic vs. psychogenic ED 💡 Board Pearl: A preserved NPT pattern suggests psychogenic ED, while absent NPT indicates organic etiology

Question 31

What device is used to measure tumescence and rigidity?

Answer 31

: RigiScan, which records penile tip and base rigidity over 2–3 nights 💡 Board Pearl: Most widely used device for noninvasive erectile function monitoring during sleep

Question 32

What threshold indicates a normal erectile event on NPT testing?

Answer 32

A: ≥60% rigidity at the penile tip for ≥10 minutes

Question 33

How many nights of NPT monitoring are typically required for accuracy?

Answer 33

: 2 to 3 nights 💡 Board Pearl: A single night is not sufficient due to natural variability in REM cycles and erection patterns

Question 34

what are common causes of false-negative NPT results?

Answer 34

A: Sleep disruption, anxiety, SSRIs, or REM suppression 💡 Board Pearl: Anything that interferes with REM sleep can reduce nocturnal erections even in healthy men

Question 35

What is the significance of having <60% rigidity or inconsistent nocturnal erections?

Answer 35

A: Suggests organic erectile dysfunction 💡 Board Pearl: These findings prompt further evaluation for vascular, neurogenic, or hormonal causes

Question 36

What are the cavernous nerves composed of, and where do they travel?

Answer 36

A: Postganglionic parasympathetic fibers, traveling through the prostate and neurovascular bundles 💡 Board Pearl: At risk during radical prostatectomy — injury causes neurogenic ED

Question 37

A man with a spinal cord injury at T12 may retain what type of erectile function?

Answer 37

A: Reflexogenic erections 💡 Board Pearl: Psychogenic erections are lost with above T11 lesions, but reflexogenic (S2–S4) may remain intact

Question 38

What is the minimum lab criterion to initiate TRT?

Answer 38

Total testosterone < 300 ng/dL on two separate morning samples with compatible symptoms.

Question 39

When should testosterone levels be measured for diagnosis?

Answer 39

Between 7–11 AM, due to diurnal variation.

Question 40

Which form of testosterone is bioavailable?

Answer 40

Free + albumin-bound testosterone.

Question 41

What condition increases SHBG and may falsely elevate total T while bioavailable T is low?

Answer 41

Hyperthyroidism, aging, liver disease.

Question 42

Which testosterone therapy provides the most stable serum levels?

Answer 42

Transdermal Gel

Question 43

has the highest transferece risk to others?

Answer 43

Transdermal Gel

Question 44

Which testosterone therapy requires minor surgical implantation?

Answer 44

subdermal pellets

Question 45

which form is least used to hepatic metabolism and poor bioavailability?

Answer 45

oral testosterone

Question 46

when should serum testosterone be checked after starting therapy?

Answer 46

3-6 montsh after initation or dose change

Question 47

For Im injections, when shoule levels me measured?

Answer 47

trough right before next injection

Question 48

what hct level is a contraindictaion to TRT?

Answer 48

>54%

Question 49

when should PSA be rechecked in men >40 on tRT?

Answer 49

6 months, then annually

Question 50

Typical therapeutic goal for total testosterone during TRT?

Answer 50

400-700 ng/Dl

Question 51

absolute contraindications to TRT

Answer 51

prostate/breast CA, HCT >54$, severe untreated OSA, infertility

Question 52

whats most common hematologic complication of TRT?

Answer 52

polycythemia

Question 53

What is relative contraindication that must be managed before TRT?

Answer 53

moderate-to-severe untreated LUTS / BPH

Question 54

which condition must be treated before initating TRT due to increased cardiovascular risk

Answer 54

untreated OSA

Question 55

man on TRT develops acne and brease tenderness, what 1st test to orer

Answer 55

serum estradiol

Question 56

first line management for elevated estradiol symptoms

Answer 56

reduce testosterone dose

Question 57

when is Aromatase inhibotor considered?

Answer 57

if estradiol is elvated and symptomatic and dose reduction failed or is not feasible

Question 58

patient on IM T has fatifue before next dose, what adjustment is needed?

Answer 58

shorten injection interval (weekly instead of Q2 weeks)

Question 59

which TRT form is most liekely to caause dermitits?

Answer 59

transdermal patch

Question 60

what gel dose is equivalent to 200 mg im weekly?

Answer 60

50 mg daily

Question 61

time to peak serum testosterone after im injection

Answer 61

24-48 hrs post injection

Question 62

when to check testosterone level after pelelt insertion

Answer 62

3 months post injections

Question 63

What hormone does hCG mimic, and what is its effect?

Answer 63

: Mimics LH → stimulates Leydig cells → increases endogenous testosterone.

Question 64

what is the mech of action of clomiphene citrate?

Answer 64

blocks estrogen feedback at the hypothalamus -> increase GnrH -> inc LH/DSH -> inc T

Question 65

which agent is non aromaitzble and avoids estrogen-related side effects?

Answer 65

DHT

Question 66

Which therapy supresses E2 (estradiol) but has bone prpblems

Answer 66

AI (aromatase inhibitors) anastrazole

Question 67

which agent raises both T and E2, when used alone?

Answer 67

hCG

Question 68

Which agent is FDA-approved for male hypogonadotropic hypogonadism?

Answer 68

hCG

Question 69

Which agent is best for young men with functional hypogonadism who desire fertility preservation?

Answer 69

clomiphene citrate

Question 70

What agent is prefered for central (secondary) hypogonadism with supressed LH/DSH, eg kallman syndrome

Answer 70

hCG + FSH

Question 71

What symptom mandates immediate discontinuation of clomiphene?

Answer 71

visual disturbance

Question 72

TRT develops gynecomastia with elevated E2

Answer 72

Reduce T dose or add an AI

Question 74

What is the advantage of clomiphene over hCG in functional hypogonadism?

Answer 74

Oral dosing, cost-effectiveness, stimulates entire HPG axis.

Question 75

What is the advantage of hCG over clomiphene in men with suppressed gonadotropins?

Answer 75

Direct stimulation of Leydig cells, preserves spermatogenesis better.

Question 76

What is the mechanism of phentolamine in ED therapy?

Answer 76

Nonselective α1/α2 antagonist → relaxes penile vascular smooth muscle. 💡 Board clue: Component of Trimix; not effective as monotherapy.

Question 77

What is yohimbine’s mechanism in ED?

Answer 77

Central α2-antagonist → enhances sympathetic tone, improves psychogenic arousal. 💡 Clinical pearl: Used mainly in psychogenic ED, not organic ED.

Question 78

best use case for yohimbine

Answer 78

oung men with psychogenic ED and low performance anxiety. 💡 Board clue: Avoid in patients with anxiety, hypertension, or heart disease.

Question 79

side effects of yohimbine?

Answer 79

Anxiety, hypertension, tachycardia. 💡 Mnemonic: “Yo, I'm hyper!” = Yohimbine can raise BP and anxiety.

Question 80

Why is oral phentolamine not widely used?

Answer 80

Modest efficacy and replaced by more effective oral therapies (PDE5i). 💡 Board clue: Works better in injectable combinations like Trimix.

Question 81

which dopamine receptors does apomorphine activate?

Answer 81

: D1 and D2 receptors in the hypothalamus. 💡 Board clue: Central acting; useful for psychogenic ED.

Question 82

Route of administration for apomorphine?

Answer 82

: Sublingual only. 💡 Clinical pearl: Swallowed dose is inactive due to liver metabolism.

Question 83

What receptor does PT-141 target?

Answer 83

Melanocortin-4 receptor (MC4R). 💡 Board clue: Works independent of NO, useful in PDE5 nonresponders.

Question 84

Mechanism of melanocortin agonists in ED?

Answer 84

Central activation → erections without sexual stimulation. 💡 Mnemonic: “MC4 = Magic Central erection”

Question 85

PT-141 is FDA-approved for...?

Answer 85

Female hypoactive sexual desire disorder (HSDD), not ED. 💡 Board clue: Common trap — approved for women, not men.

Question 86

: Trazodone acts on which receptors for ED?

Answer 86

5-HT2C (agonist) and 5-HT1A (antagonist). 💡 Board tip: Associated with priapism – know the receptor balance.

Question 87

Only FDA-approved injectable agent for ED?

Answer 87

Alprostadil (PGE1). 💡 Pearl: Caverject and Edex are brand names.

Question 88

Mechanism of alprostadil?

Answer 88

↑cAMP via adenylate cyclase → smooth muscle relaxation. 💡 Tip: Acts independent of NO.

Question 89

: What’s in Trimix?

Answer 89

Alprostadil + papaverine + phentolamine. 💡 Mnemonic: “Tri-force: relaxes arteries, blocks constriction, opens channels”

Question 90

How is priapism from ICI treated?

Answer 90

Phenylephrine 500 mcg/mL intracavernosally. 💡 Warning: Avoid if patient is on MAOIs.

Question 91

Why avoid phenylephrine in MAOI users?

Answer 91

htn crisis

Question 92

proper ICI injection site

Answer 92

Lateral penile shaft, 10 and 2 o'clock positions. 💡 Pearl: Avoid dorsal vein and urethra.

Question 93

What does MUSE stand for?

Answer 93

Medicated Urethral System for Erection. 💡 Board tip: Delivers alprostadil pellet into urethra.

Question 94

Drug used in MUSE?

Answer 94

Alprostadil (PGE1), same mech as ICI, different route

Question 95

Response rate to MUSE therapy?

Answer 95

A: ~50% response; ~30% full erection. 💡 Tip: Add ACTIS ring to improve rigidity.

Question 96

most common side effect of MUSE

Answer 96

URogenital Pain, ~33% users report discomfort

Question 97

why avoid MUSE in unprotected sex with pregnant partners?

Answer 97

alprostadil may cause vaginal irritation or contractions. 💡 Board Pearl: Use condom during intercourse if partner is pregnant.

Question 98

What is the gold standard treatment for refractory ED?

Answer 98

Penile prosthesis implantation 💡 Pearl: Definitive solution after failure of oral, injectable, and device therapies

Question 99

What is considered third-line therapy for ED?

Answer 99

A: Surgical implantation of a penile prosthesis 💡 Pearl: “Third-line” refers to treatment sequence, not efficacy

Question 100

Ideal candidate profile for penile revascularization surgery?

Answer 100

Young (<55), non-smoker, non-diabetic with focal arterial injury 💡 Pearl: Most often post-trauma arteriogenic ED

Question 101

Key surgical technique for revascularization?

Answer 101

A: Inferior epigastric artery to dorsal penile artery bypass 💡 Clue: Improves arterial inflow directly

Question 102

Q: What is the strict NIH definition of erectile dysfunction (ED)?

Answer 102

Persistent inability to attain and/or maintain an erection sufficient for satisfactory sexual performance (≥3 months).

Question 103

Name the 5 domains of the IIEF.

Answer 103

Mnemonic for IIEF Domains: "Every One Should Enjoy Intimacy" Letter Domain What It Assesses E Erectile Function Ability to achieve and maintain erection O Orgasmic Function Ability to reach orgasm S Sexual Desire Level of libido and interest E Intercourse Satisfaction Satisfaction during intercourse I Overall Satisfaction General satisfaction with sexual life