A male patient, age unspecified, experiences erectile dysfunction, achieving an erection that lasts only a few minutes before becoming soft again, what could be the cause and treatment for this condition?

Erectile Dysfunction with Loss of Rigidity During Intercourse

This patient is experiencing erectile dysfunction (ED) characterized by inability to maintain an erection, which requires treatment with phosphodiesterase-5 inhibitors (PDE5i) as first-line therapy after ruling out reversible causes and cardiovascular risk factors. 1, 2, 3

Initial Evaluation

Critical History Elements

• Duration and pattern: Determine if this is lifelong (primary) or acquired (secondary) ED, as secondary ED has better treatment outcomes 4
• Morning erections and masturbatory rigidity: Presence suggests psychogenic component; absence suggests organic pathology 4
• Cardiovascular risk factors: ED shares common risk factors with cardiovascular disease including diabetes, hypertension, dyslipidemia, obesity, and lack of exercise 2, 3
• Medication review: Many drugs contribute to ED and should be identified 3, 5
• Partner and relationship factors: Including partner involvement optimizes outcomes 6

Required Laboratory Testing

• Fasting glucose levels 3
• Fasting lipid profile 3
• Morning testosterone level (if symptoms suggest hypogonadism, as low testosterone correlates with erectile dysfunction) 7
• Prostate-specific antigen in select cases 3

Treatment Algorithm

First-Line: PDE5 Inhibitors

PDE5 inhibitors (sildenafil, tadalafil, vardenafil, avanafil) achieve 60-65% success rates for intercourse completion, even in men with diabetes, hypertension, and spinal cord injury. 3

Critical Prescribing Instructions

• Sexual stimulation is required for PDE5i to work; the medication does not cause automatic erections 1
• Timing matters: Take medication before anticipated sexual activity with adequate time for absorption 1
• Adequate arousal is essential: The medication enhances erectile function but requires psychological and physical arousal 8
• Clear instructions are critical to realize full benefits and avoid treatment failure from improper use 9

Absolute Contraindications

• Never prescribe with nitrates (nitroglycerin, isosorbide) or recreational "poppers" (amyl/butyl nitrite) due to potentially fatal blood pressure drops 1
• Never prescribe with guanylate cyclase stimulators (riociguat) 1
• For tadalafil specifically, at least 48 hours must elapse after the last dose before nitrate administration can be considered in emergencies 1

Monitoring Requirements

• Cardiovascular status, especially in men with heart disease, as sexual activity places extra strain on the heart 1
• Blood pressure effects, particularly in men with autonomic dysfunction 1

Second-Line Options (for PDE5i Failures)

• Intracavernosal injection therapy with alprostadil is effective in men who fail oral agents 3
• Vacuum constriction devices 2, 5
• Intraurethral alprostadil 2

Third-Line: Surgical Treatment

• Penile prosthesis implantation achieves high satisfaction rates and is reserved for refractory cases 2, 3

Concurrent Management Strategies

Lifestyle Modifications (Essential)

• Address obesity and lack of exercise 3
• Reduce cardiovascular risk factors 3
• These interventions improve both ED and overall cardiovascular health 3

Psychosexual Counseling

• For secondary psychogenic ED: Physician reassurance about normal erectile capacity with 3-month follow-up achieves 71% remission rates 4
• For primary psychogenic ED: Requires more intensive intervention including behavioral therapy or pharmacological erection program 4
• Anxiety and unrealistic expectations commonly result in poor PDE5i response despite adequate physiological function 9

Treat Comorbid Conditions First

• If erectile dysfunction coexists with other sexual dysfunctions (ejaculatory disorders, orgasmic dysfunction), treat the ED first as these conditions share common risk factors and ED treatment may resolve other issues 7, 8
• Erectile dysfunction and orgasmic dysfunction are distinct: 20% of diabetic men with ED experience orgasmic dysfunction independently, requiring separate assessment 8

Common Pitfalls to Avoid

Patient Education Failures

• Inadequate instructions about timing, need for sexual stimulation, and realistic expectations lead to perceived treatment failure when the medication would otherwise work 9
• Patients must understand that PDE5i enhances natural erectile response but does not create automatic erections 1

Cardiovascular Screening Gaps

• Failing to assess cardiovascular disease before prescribing PDE5i, as ED is often the first manifestation of systemic vascular disease 2, 3
• Missing contraindications to sexual activity in men with severe heart disease 1

Premature Surgical Referral

• Penile prosthesis should only be considered after exhausting medical options including proper PDE5i trials, injection therapy, and vacuum devices 2, 3