Which nerves mediate the pain of priapism in a patient who took tadalafil (15 mg) and sildenafil (60 mg) and now has a persistent hard, discolored, numb penis?

Pain in Ischemic Priapism: Neuroanatomic Basis

The pain of ischemic priapism is mediated by the dorsal nerve of the penis, a terminal branch of the pudendal nerve, which transmits nociceptive signals from the ischemic corpus cavernosum and surrounding penile tissues. 1

Neuroanatomic Pathway

The dorsal nerve of the penis runs along the dorsum of the penile shaft beneath Buck's fascia and is responsible for:

• Sensory innervation of the glans and penile skin
• Pain transmission from the corpus cavernosum during ischemic episodes
• Proprioceptive feedback from penile structures

In your patient's case with combined tadalafil (15 mg) and sildenafil (60 mg) overdose, the numbness suggests potential nerve compression or ischemic injury to the dorsal nerve itself, while the severe pain originates from:

1. Ischemic tissue damage in the corpus cavernosum (primary source)
2. Compartment syndrome-like pressure on nerve endings
3. Acidosis and metabolic waste accumulation stimulating nociceptors

Clinical Context for This Patient

The 2022 AUA/SMSNA guidelines emphasize that pain is NOT a reliable indicator of priapism severity or urgency 2. Many patients experience pain from:

• The injection medication itself (not applicable here with oral PDE5 inhibitors)
• Full engorgement and tissue stretching
• Progressive ischemia (most relevant in this case)

Critical point: The combination of a hard, discolored, AND numb penis after 2+ days suggests advanced ischemic priapism with potential nerve damage from prolonged compression and ischemia 1, 3.

Immediate Management Implications

This patient requires urgent intervention regardless of pain level:

• Blood gas analysis from corpus cavernosum to confirm ischemia 2
• Immediate corporal aspiration (up to 500 mL) with or without intracavernosal phenylephrine 4
• If failed: distal corporoglanular shunt (T-shunt) 5
• Monitor for compartment-related nerve injury

The numbness is particularly concerning as it may indicate:

• Pudendal nerve compression at the inferior border of the pubis 1
• Direct ischemic injury to the dorsal nerve from prolonged priapism
• Poor prognostic sign for erectile function recovery 3

Warning: The FDA labels for both sildenafil and tadalafil specifically warn about priapism risk, stating that erections >4 hours require immediate medical attention to prevent permanent penile tissue damage and loss of potency 6, 7. At 2+ days with discoloration and numbness, this patient is at extremely high risk for permanent erectile dysfunction and may require early penile prosthesis consideration 8.