Can I give Vistaril (hydroxyzine) to a patient on fluoxetine and bupropion?

Hydroxyzine (Vistaril) Use with Fluoxetine and Bupropion

Hydroxyzine can be safely administered to patients taking fluoxetine and bupropion, but caution is warranted due to potential additive sedative effects and a small theoretical risk of QT prolongation.

Safety Assessment

Hydroxyzine (Vistaril) is generally safe to use in combination with fluoxetine and bupropion, with some important considerations:

• Hydroxyzine does not have significant serotonergic activity that would increase the risk of serotonin syndrome when combined with fluoxetine (SSRI) 1
• Unlike some other medications that can interact with SSRIs, hydroxyzine does not inhibit cytochrome P450 2D6 pathway, which is how some drug interactions with fluoxetine occur 2
• Bupropion and fluoxetine together have a theoretical risk of serotonin syndrome, though this is rare at standard therapeutic doses 2, 3

Potential Concerns

Sedation

• Hydroxyzine has sedative properties that may be additive with any sedative effects from fluoxetine
• Monitor for excessive sedation, especially when initiating therapy

QT Prolongation

• Hydroxyzine has a small risk of QT prolongation at higher doses
• Fluoxetine has minimal QT prolongation risk compared to other SSRIs
• Consider baseline ECG in patients with other risk factors for QT prolongation:
  • Electrolyte abnormalities
  • Cardiovascular disease
  • Concomitant QT-prolonging medications
  • Advanced age

Anticholinergic Effects

• Both hydroxyzine and fluoxetine have mild anticholinergic properties
• Monitor for dry mouth, constipation, urinary retention, and blurred vision
• Use with caution in elderly patients who are more sensitive to anticholinergic effects 1

Dosing Recommendations

• Start with a lower dose of hydroxyzine (25mg) rather than the standard dose (50mg)
• Administer at bedtime initially to assess for excessive sedation
• Titrate dose based on clinical response and tolerability
• Avoid abrupt discontinuation of any of these medications

Alternative Options

If concerned about potential interactions:

1. Topical nasal decongestants (if treating nasal congestion) are safer options with minimal systemic absorption 4
2. Non-pharmacological approaches such as saline nasal sprays or nasal irrigation if treating congestion 4
3. Loratadine or cetirizine (if treating allergic symptoms) have fewer sedative and anticholinergic effects than hydroxyzine

Monitoring Recommendations

• Assess for excessive sedation within 1-2 hours after first dose
• Monitor for signs of serotonin syndrome (though risk is low):
  • Confusion, agitation, tremors
  • Muscle twitching, sweating
  • Elevated heart rate and blood pressure
  • Hyperthermia
• If any concerning symptoms develop, discontinue hydroxyzine and seek immediate medical attention

Key Takeaways

1. Hydroxyzine can be used with fluoxetine and bupropion with appropriate caution
2. Start with lower doses and monitor for sedation
3. Be vigilant for any signs of serotonin syndrome, though this risk is theoretical and low
4. Consider alternative non-sedating antihistamines if excessive sedation is a concern