Can Vistaril (hydroxyzine) cause priapism?

Hydroxyzine (Vistaril) Can Cause Priapism

Yes, hydroxyzine (Vistaril) can cause priapism, as documented in case reports, though it is a rare adverse effect related to its alpha-adrenergic blocking properties. 1

Mechanism of Action

Hydroxyzine-induced priapism occurs through:

• Alpha-adrenergic receptor blockade in the corpora cavernosa of the penis
• Inhibition of the normal sympathetic input necessary for penile detumescence
• Disruption of the balance between tumescence and detumescence mechanisms

Risk Factors and Considerations

• Priapism is more commonly associated with:

  • Antipsychotic medications (account for ~50% of drug-related priapism cases) 2
  • Alpha-blockers (like terazosin) 3
  • Certain antidepressants

• Hydroxyzine-related priapism:

  • Can occur at both therapeutic doses and in overdose situations
  • Has been documented in case reports, including a patient who took hypercompliant doses (200-600 mg) 1
  • May occur without warning and without dose-dependent relationship

Clinical Implications

• Priapism is a urologic emergency requiring immediate intervention
• Defined as a persistent, painful erection lasting more than 4 hours without sexual stimulation
• Ischemic priapism (most common type) is characterized by:
  • Blood gas values showing hypoxia (PO2 ≤30 mmHg)
  • Hypercapnia (PCO2 ≥60 mmHg)
  • Acidosis (pH <7.25) 4

Management of Hydroxyzine-Induced Priapism

If priapism occurs while taking hydroxyzine:

1. Immediate discontinuation of hydroxyzine
2. Urgent urological consultation as this is a medical emergency
3. First-line treatment: Intracavernosal phenylephrine (preferred sympathomimetic agent)
   • Diluted with normal saline to 100-500 μg/mL
   • Administered in 1 mL injections every 3-5 minutes for up to 1 hour 5, 4
4. Aspiration with or without irrigation if phenylephrine alone is unsuccessful 5
5. Surgical intervention (distal shunting) if pharmacologic measures fail 5

Monitoring During Treatment

• Blood pressure and heart rate monitoring is essential during treatment with sympathomimetics 5
• ECG monitoring is recommended in patients with cardiovascular risk factors 4
• Patients should be observed for symptoms like hypertension, headache, bradycardia, tachycardia, and cardiac arrhythmias 5

Prevention and Patient Education

• Patients taking hydroxyzine should be informed about this rare but serious side effect
• Early recognition and reporting of prolonged erections (>4 hours) is critical
• Prompt treatment is essential to prevent permanent erectile dysfunction, which becomes increasingly likely after 18-36 hours of ischemia 4

Clinical Pearls

• Time is critical in managing priapism - treatment efficacy decreases significantly after 48 hours
• Risk of permanent erectile dysfunction increases dramatically after 18 hours of ischemia
• Phenylephrine is the preferred agent for treatment due to its selective alpha-1 adrenergic properties and lower risk of cardiovascular side effects compared to other sympathomimetics 5

When prescribing hydroxyzine, clinicians should be aware of this rare but potentially serious adverse effect and educate patients accordingly.