What causes prolonged erection and ejaculatory dysfunction?

Causes of Prolonged Erection and Ejaculatory Dysfunction

Prolonged Erection (Priapism)

Prolonged erection lasting >4 hours is a urologic emergency requiring immediate intervention to prevent permanent erectile dysfunction, with the risk of irreversible damage increasing dramatically after 36 hours. 1

Primary Causes of Ischemic Priapism

• Intracavernosal injection therapy is the most common iatrogenic cause, occurring in 2.7% with prostaglandin E1, 5.0% with prostaglandin E1 plus phentolamine, and 8.3% with papaverine 2

• Medications including:

  • Psychoactive drugs (trazodone, SSRIs like paroxetine) through alpha2-adrenergic receptor antagonism 3, 4
  • Antipsychotics and antidepressants 5
  • Recreational drugs 1

• Hematologic disorders, particularly sickle cell disease, which causes veno-occlusive priapism through abnormal red blood cell sickling 1, 6

• Idiopathic causes account for a significant proportion when no clear etiology is identified 7

• Malignancies, especially genitourinary cancers and leukemia 1, 6

Non-Ischemic Priapism Causes

• Perineal or penile trauma causing arteriovenous fistula formation with unregulated arterial inflow 1, 8

• This represents high-flow priapism with normal oxygenation and is not an emergency 1

Pathophysiology

The mechanism involves failure of detumescence through:

• Impaired venous outflow (ischemic type) leading to hypoxic (pO₂ <30 mmHg), hypercarbic (pCO₂ >60 mmHg), and acidotic (pH <7.25) blood 1, 8
• Excessive arterial inflow (non-ischemic type) with normal blood gas values 1, 8
• Prolonged smooth muscle relaxation preventing normal penile flaccidity 2

Critical Time-Dependent Tissue Damage

• <12 hours: Minimal permanent damage if treated promptly 8
• 12-24 hours: Progressive smooth muscle edema and early atrophy 1
• >36 hours: Permanent erectile dysfunction is virtually certain with no recovery of erectile function 1
• 24-48 hours: Widespread corporal necrosis occurs 8

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Ejaculatory Dysfunction

Primary Causes of Ejaculatory Failure

Ejaculatory dysfunction is a separate entity from priapism and has distinct etiologies:

• Medications are the most common reversible cause:

  • SSRIs (selective serotonin reuptake inhibitors) are the primary pharmacologic cause of delayed or absent ejaculation 9
  • Alpha-blockers affecting sympathetic nervous system function
  • Antipsychotics and other psychotropic medications

• Neurologic disorders affecting the ejaculatory reflex pathway:

  • Spinal cord injury
  • Diabetic neuropathy
  • Multiple sclerosis
  • Surgical damage to pelvic nerves

• Anatomic abnormalities:

  • Retrograde ejaculation from bladder neck dysfunction
  • Post-surgical changes (prostatectomy, retroperitoneal surgery)

• Psychological factors including performance anxiety and relationship issues 9

Important Clinical Distinction

These are two separate conditions that should not be conflated: Priapism involves prolonged erection requiring emergency treatment 1, while ejaculatory dysfunction is a chronic sexual health issue requiring different evaluation and management 9. The only overlap occurs when certain medications (like trazodone) can paradoxically cause both priapism and ejaculatory changes 3, 4.

Key Clinical Pitfall

Do not delay treatment of priapism to investigate ejaculatory concerns—any erection >4 hours requires immediate corporal blood gas analysis and treatment with intracavernosal phenylephrine 1. Ejaculatory dysfunction can be addressed after the emergency is resolved.