Lesson
Sexual Health Without Assumptions
Sexual dysfunction is not one symptom. A respectful assessment separates the affected domain, the patient's own distress and goals, and the biological, psychological, relational, and medication contexts that can interact.
- Desire and arousal
- Erection and orgasm
- Pain
- Medication effects
- Patient autonomy
Desire, arousal, erection, orgasm, pain, and satisfaction are related but distinct
Health, medicines, mood, relationship context, and goals shape the presentation
Treat reversible causes and match therapy to the person rather than a label alone
Separate the domains
Ask about desire, subjective arousal, genital response, erection, orgasm, ejaculation, pain, satisfaction, onset, context, and consistency. One domain can alter another, but a treatment for erection does not automatically treat desire, pain, or relationship distress.
Use inclusive history
Ask which body parts, activities, partners, and goals are relevant without presuming identity, orientation, anatomy, or partner involvement. Include mood, trauma, sleep, substances, relationship safety, reproductive goals, pelvic symptoms, and chronic disease only to the degree needed for care.
Review every exposure
Antidepressants, antipsychotics, opioids, antiandrogens, 5-alpha-reductase inhibitors, some antihypertensives, alcohol, nicotine, and other substances can affect sexual function. Preserve the original indication and coordinate changes rather than stopping therapy abruptly.
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Lesson
Erectile Dysfunction as a Clinical Signal
Erectile dysfunction can be a quality-of-life concern and an early marker of systemic disease. Evaluation should reveal the mechanism, cardiovascular context, reversible contributors, and whether sexual activity is currently safe.
- Medical and sexual history
- Cardiovascular risk
- Morning testosterone
- Medication review
- Selective testing
Onset, consistency, rigidity, libido, morning erections, medicines, and distress
Cardiovascular, neurologic, endocrine, pelvic, and medication clues guide testing
Use testosterone, metabolic assessment, or specialized testing when the result can change care
Build the core evaluation
Characterize onset, severity, consistency, morning and masturbatory erections, rigidity, maintenance, libido, ejaculation, pain, prior treatment, pelvic surgery or radiation, neurologic symptoms, medications, substances, mood, and relationship context. Examine cardiovascular, endocrine, neurologic, vascular, and genital findings as appropriate.
Recognize the vascular signal
ED is a cardiovascular risk marker. Review exertional symptoms, functional capacity, blood pressure, glycemia, lipids, smoking, weight, sleep, and family history. New chest symptoms, unstable disease, or uncertainty about fitness for sexual activity requires cardiovascular evaluation before unsupervised treatment.
Order tests that can change care
Current AUA guidance supports a morning total testosterone level in men with ED. Use glucose or A1c, lipids, renal function, thyroid testing, prolactin, or specialized vascular and neurologic studies selectively according to the history, examination, and decision being considered.
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Lesson
Nitric Oxide, cGMP, and PDE5
Erection depends on coordinated neural and endothelial signaling, cavernosal smooth-muscle relaxation, arterial inflow, and venous compression. PDE5 inhibitors preserve a signal generated by sexual stimulation rather than initiating desire.
- Nitric oxide
- Soluble guanylate cyclase
- cGMP
- Calcium
- PDE5 selectivity
Neural and endothelial stimulation activates soluble guanylate cyclase
Lower intracellular calcium relaxes cavernosal smooth muscle and increases inflow
Reduced cGMP breakdown supports an erection when sexual stimulation is present
Generate the signal
Parasympathetic and endothelial nitric oxide activates soluble guanylate cyclase in cavernosal smooth muscle. Rising cGMP lowers intracellular calcium, relaxes smooth muscle, increases arterial inflow, and supports compression of venous outflow.
Preserve rather than create
PDE5 hydrolyzes cGMP. Sildenafil, tadalafil, vardenafil, and avanafil inhibit that breakdown, so adequate neural stimulation and nitric oxide generation remain necessary. They do not directly create sexual desire or guarantee an erection without stimulation.
Connect structure to clinical behavior
Each inhibitor uses a different molecular scaffold to occupy the PDE5 catalytic site. Differences in potency, selectivity, protein binding, CYP3A4 metabolism, half-life, food effect, and off-target activity produce distinct dosing and adverse-effect profiles despite a shared target.
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Lesson
Selecting and Using a PDE5 Inhibitor
The best oral agent is the one whose timing, duration, administration, organ-function limits, adverse effects, and interactions fit the patient. Milligram doses cannot be substituted across products.
- Sildenafil
- Tadalafil
- Vardenafil
- Avanafil
- Administration technique
Plan around food, timing, interactions, and the required stimulation
Use as needed or daily and account for renal function and prolonged nitrate concern
Use its labeled timing and strict CYP3A4 limits rather than assuming a class schedule
Match timing and duration
Sildenafil is commonly started at 50 mg about one hour before activity. Vardenafil has a similar planned-use profile. Tadalafil supports a longer response window and either as-needed or daily use. Avanafil can be taken closer to anticipated activity at its labeled dose. All require stimulation and no product should be used more often than labeled.
Account for food and exposure
A high-fat meal can delay or reduce the apparent response of sildenafil and vardenafil and can delay avanafil onset. Tadalafil can be taken without regard to food. Review age, renal and hepatic function, CYP3A4 modifiers, and alpha blockers before selecting a starting dose.
Distinguish adverse-effect profiles
Headache, flushing, dyspepsia, nasal symptoms, and dizziness can occur across the class. Sildenafil and vardenafil can cause color-vision effects, tadalafil more often causes back pain or myalgia, and vardenafil requires specific QT caution. Use the exact current label for product-specific decisions.
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Lesson
PDE5 Safety and Interaction Control
PDE5 inhibitor safety depends on stopping dangerous cGMP combinations, managing additive hypotension and metabolism, and teaching the rare symptoms that cannot wait.
- Nitrates
- Riociguat and vericiguat
- Alpha blockers
- CYP3A4
- Priapism and sensory loss
Combined cGMP signaling can produce profound hypotension
Confirm hemodynamic stability and begin the PDE5 inhibitor at the lowest labeled dose
An erection beyond four hours or sudden sensory loss requires urgent evaluation
Block cGMP stacking
Organic nitrates in any form and soluble guanylate cyclase stimulators such as riociguat are contraindicated because the combined pathway can produce profound hypotension. Current avanafil labeling also names vericiguat. If a nitrate becomes medically necessary for a life-threatening situation, current labeling requires at least 12 hours after avanafil or 48 hours after tadalafil, close supervision, and hemodynamic monitoring. Sildenafil labeling does not establish a safe post-dose interval. A patient with chest pain should stop activity, seek emergency care, and report the exact drug and time rather than self-administer a nitrate.
Control additive exposure
A patient should be stable on alpha-blocker therapy before a PDE5 inhibitor is introduced at the lowest labeled dose. Review antihypertensives, volume depletion, alcohol, autonomic dysfunction, and CYP3A4 inhibitors. Product rules differ, including complete avoidance of avanafil with strong CYP3A4 inhibitors.
Teach urgent thresholds
An erection lasting more than four hours requires emergency evaluation. Sudden vision loss or sudden hearing loss also requires prompt discontinuation and urgent assessment. Avoid combining multiple ED therapies without an explicitly supervised plan.
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Lesson
When Oral Therapy Appears to Fail
A failed tablet is often an incomplete trial. Technique, dose, stimulation, expectations, food, adherence, diagnosis, testosterone, vascular risk, and psychosocial context should be audited before escalation.
- Correct technique
- Dose titration
- Repeated attempts
- Testosterone deficiency
- Shared escalation
Confirm the exact product, adequate dose, stimulation, food effect, and repeated attempts
Look again at vascular risk, testosterone, medicines, anxiety, pain, and relationship context
Offer devices, alprostadil, injections, or prosthesis discussion through shared decisions
Audit the trial
Confirm the exact product, dose, timing, food, stimulation, number of attempts, adherence, and adverse effects. Correct technique and titrate within labeling. Some patients need several properly conducted attempts before judging response.
Revisit the mechanism
Reassess vascular disease, diabetes, neurologic injury, pelvic surgery or radiation, medicine effects, depression, performance anxiety, pain, relationship context, and morning testosterone. Confirmed testosterone deficiency may reduce PDE5 response, but empiric testosterone without diagnosis is not appropriate.
Open the full option set
Another PDE5 inhibitor, a vacuum device, intraurethral or intracavernosal therapy, and penile prosthesis can all be discussed according to safety and preference. Modern shared decisions do not require a rigid ladder before an informed patient can consider a more invasive option.
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Lesson
Devices, Alprostadil, and Prostheses
Nonoral ED treatment can create rigidity mechanically, deliver a local vasodilator, or replace erectile mechanics surgically. Each option exchanges systemic exposure for technique, local adverse effects, or procedural commitment.
- Vacuum erection device
- Intraurethral alprostadil
- Intracavernosal alprostadil
- Priapism
- Penile prosthesis
Use negative pressure and a constriction ring with technique and time limits
Titrate intraurethral or intracavernosal therapy with priapism and fibrosis counseling
Discuss irreversible surgery, infection, mechanical failure, and expected function
Use mechanical pressure safely
Vacuum devices draw blood into the penis and a constriction ring maintains rigidity. Teach assembly, lubrication, ring placement, the manufacturer's time limit, bruising and discomfort, impaired sensation, and considerations with anticoagulation or bleeding disorders.
Titrate prostaglandin locally
Alprostadil is prostaglandin E1. Intraurethral and intracavernosal routes require in-office testing or titration, technique training, and counseling about penile pain, hypotension, bleeding, prolonged erection, and priapism. Intracavernosal users rotate lateral sites and receive periodic examination for fibrosis.
Discuss surgery honestly
Inflatable or malleable penile prostheses can produce high satisfaction but permanently alter erectile anatomy. Discuss infection, mechanical failure, revision, expected length and sensation, recovery, and device operation before an irreversible decision.
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Lesson
Evaluating Low Sexual Desire
Low desire is not automatically a disorder. HSDD requires an acquired, generalized change that causes marked distress or interpersonal difficulty and is not better explained by another medical, psychiatric, relational, medication, or substance factor.
- Acquired
- Generalized
- Marked distress
- Exclusion
- Autonomy
The change occurs across situations and causes marked distress or interpersonal difficulty
Medical, psychiatric, relationship, medication, pain, and substance factors may better explain the concern
Treatment is not intended to enhance performance or satisfy someone else's expectation
Confirm the labeled pattern
Acquired means the concern developed after a period without the problem. Generalized means it occurs across types of stimulation, situations, and partners. The concern must produce marked distress or interpersonal difficulty.
Find better explanations
Assess mood and anxiety, trauma, pain, genitourinary symptoms, endocrine and neurologic disease, sleep, substances, relationship safety and satisfaction, life stress, menopause symptoms, and medication effects. Treating an explanatory cause may be more appropriate than an HSDD medicine.
Protect autonomy
Neither flibanserin nor bremelanotide is indicated to enhance sexual performance. Low desire without personal distress does not require medicalization. Partner participation can be useful only when the patient wants it and feels safe.
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Lesson
Flibanserin Under the Current Label
Flibanserin is a daily centrally acting treatment for acquired generalized HSDD in women younger than 65. Its benefit trial is inseparable from bedtime dosing, alcohol timing, CYP interactions, liver function, and alertness counseling.
- Women younger than 65
- 100 mg at bedtime
- Alcohol timing
- CYP3A4
- Eight-week assessment
Stop after eight weeks without improvement and never double a missed dose
Use current timing instructions and avoid driving for at least six hours after a dose
Moderate or strong CYP3A4 inhibitors and any hepatic impairment are contraindications
Apply the updated indication
Current labeling includes women younger than 65 with acquired generalized HSDD after appropriate exclusions. The label is no longer limited to premenopausal women. Give 100 mg at bedtime and stop after eight weeks if symptoms have not improved.
Control hypotension and sedation
Wait at least two hours after one or two standard alcoholic drinks before the bedtime dose, skip the dose after three or more drinks that evening, and avoid alcohol until the next day after dosing. Avoid driving or other full-alertness activity for at least six hours after each dose and until individual effects are known.
Prevent exposure errors
Moderate or strong CYP3A4 inhibitors and any hepatic impairment are contraindications. Multiple weak CYP3A4 inhibitors, strong CYP2C19 inhibitors, oral contraceptives, CNS depressants, digoxin, and CYP3A4 inducers require review. Use the labeled washout periods when changing a moderate or strong CYP3A4 inhibitor.
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Lesson
Bremelanotide as Needed
Bremelanotide is an as-needed melanocortin receptor agonist for premenopausal women with acquired generalized HSDD. It trades daily exposure for an injection-associated window of blood-pressure change, nausea, and other risks.
- Premenopausal indication
- Subcutaneous injection
- Blood pressure
- Nausea
- Hyperpigmentation
Use at least 45 minutes before anticipated activity, no more than once daily or eight times monthly
Uncontrolled hypertension or known cardiovascular disease is a contraindication
Reassess persistent nausea, focal hyperpigmentation, gastric emptying, and oral naltrexone exposure
Use the exact schedule
Inject 1.75 mg subcutaneously in the abdomen or thigh at least 45 minutes before anticipated activity. Do not exceed one dose in 24 hours or eight doses per month. Stop after eight weeks without improvement.
Screen the cardiovascular window
Each dose transiently raises blood pressure and reduces heart rate, usually resolving within 12 hours. Uncontrolled hypertension or known cardiovascular disease is a contraindication. Assess cardiovascular risk and confirm good pressure control before and during treatment.
Manage noncardiac risks
Nausea is common and can be treatment limiting. Focal hyperpigmentation may not completely resolve and occurs more often with frequent dosing and in darker skin. Slower gastric emptying can alter oral-drug absorption, oral naltrexone exposure can fall substantially, and effective contraception is advised with discontinuation if pregnancy is suspected.
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Module test
Check the connections.
Each attempt draws 10 questions from the complete 112 question bank.
Each attempt draws a fresh set and rearranges the answer choices.
References
Current clinical foundation.
Lecture material was synthesized with the following contemporary guidance. Verify local policy and current guidance before applying clinical information.
- American Urological Association, Erectile Dysfunction Guideline
- DailyMed, Viagra sildenafil prescribing information
- DailyMed, tadalafil prescribing information
- DailyMed, vardenafil prescribing information
- DailyMed, Stendra avanafil prescribing information
- DailyMed, Caverject alprostadil prescribing information
- DailyMed, Addyi flibanserin prescribing information, revised December 2025
- DailyMed, Vyleesi bremelanotide prescribing information