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Palagiri et al

Figure 1. Noncontrast head computed tomography demonstrating a hyperdense lesion involving the left pons, with extension inferiorly
and laterally in the middle cerebellar peduncle.

recreational drug use, herbal medication use, hematologic
disorders, or malignancy that can contribute to priapism. His
vital signs upon presentation were within normal limits,
including a BP of 121/78 mm Hg, pulse of 70 beats/min, and
weight of 95 kg. His physical examination was unremarkable
except for a fully erect penis.
After local injection of 2 rounds (1 hour apart) of 0.5 mL
of 100 µg phenylephrine (10 mg/mL phenylephrine diluted
to a concentration of 200 µg/mL) into each corpus cavernosa,
priapism resolved rapidly. Within 5 minutes, the patient
began experiencing headaches, dyspnea, and excruciating
chest pain. He appeared diaphoretic, and his BP at that time
was elevated to 240/130 mm Hg. His electrocardiogram
showed new ST-segment depressions in the inferolateral
leads. An immediate troponin returned at 0.05 ng/mL. Within
10 minutes of developing these symptoms, his BP normalized spontaneously to 138/79 mm Hg. On neurological
examination, new-onset right arm and leg weakness (strength
3/5), right pronator drift, and partial left hemianopia were
noted. A STAT noncontrast computed tomography (CT)
showed hyperdense lesions in the midbrain involving the left
pons with inferior and lateral extension in the middle cerebellar peduncle (Figure 1). Magnetic resonance imaging
(MRI) of the brain 4 hours later demonstrated the same hemorrhage with mild surrounding edema (Figure 2). The hemorrhage had a tubular appearance on T2-weighted images.
The CT angiography of the head, neck, and chest did not
reveal evidence of aneurysms, arteriovenous malformations,
or aortic dissection. His troponin elevation was attributed to

a type 2 myocardial infarction; troponin peaked at 0.69 ng/
mL (4 hours from symptom onset) and then trended down,
and his chest pain and Electrocardiogram (EKG) changes
resolved after spontaneous normalization of BP.
The patient was admitted to intensive care unit for conservative management of hypertensive emergency and intracranial
hemorrhage. Priapism recurred during hospitalization, necessitating a distal shunt placement, which resulted in detumescence. Patient was hospitalized for a total of 6 days during
which his neurologic deficits progressively improved; however, mild diplopia and gait impairment persisted at discharge.

Case Discussion
Priapism occurs when the penis remains erect for hours in
the absence of stimulation or after the stimulation has ended.
Priapism is a urological emergency; untimely diagnosis and
intervention can lead to penile fibrosis and ultimately erectile dysfunction. Diagnosis is made by history and physical
examination; sometimes, blood gas analysis of the aspirated
blood from the penis or ultrasound can be used to support the
diagnosis.6 One of the common modality of treatment is
intracavernosal injection of sympathomimetic agent especially phenylephrine because of the rapid onset and shorter
duration of action.7-9
Use of intracavernosal phenylephrine is off-label, however recognized as standard of care. Systemic toxicity is
rarely reported after intracavernosal injection of adrenergic
agents.10-12 In a case study by Muruve and Hosking, there

Hospital Pharmacy - June 2019

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