Can Atarax (hydroxyzine) cause hypotension?

Can Atarax (Hydroxyzine) Cause Hypotension?

Yes, hydroxyzine (Atarax) can cause hypotension, particularly in overdose situations or in susceptible individuals. The FDA drug label specifically mentions hypotension as a potential adverse effect in cases of overdose 1.

Mechanisms and Risk Factors

• Hydroxyzine's potential to cause hypotension is most commonly associated with:

  • Overdose situations, where hypotension may accompany hypersedation 1
  • Anaphylactic reactions, which can present with severe hypotension and bronchospasm 2
  • QT prolongation in overdose, which may lead to cardiac arrhythmias affecting blood pressure 1

• Hydroxyzine may interfere with normal blood pressure regulation through:

  • Antihistaminic effects that can impact vascular tone 3
  • Potential cardiac effects including abnormal ventricular repolarization when given in substantial doses 4

Clinical Considerations

• Risk factors that may increase the likelihood of hydroxyzine-induced hypotension:
  • Concurrent use of other medications that affect blood pressure, particularly:
    • Alpha-1 blockers (doxazosin, prazosin, terazosin), which are associated with orthostatic hypotension 5
    • Direct vasodilators (hydralazine, minoxidil) 5
    • Central alpha-2 agonists (clonidine, methyldopa, guanfacine) 5
  • Concomitant use of medications that may augment cardiac effects, such as phenothiazines, tricyclic antidepressants, or antiparkinson drugs 4
  • Advanced age, as older adults are more susceptible to orthostatic hypotension from medications 6

Management of Hydroxyzine-Induced Hypotension

• For mild hypotension:

  • Discontinuation of the medication may be sufficient 1
  • Supportive care with monitoring of vital signs 1

• For severe hypotension (as in overdose or anaphylactic reaction):

  • Intravenous fluids are first-line treatment 1
  • If needed, vasopressors such as levarterenol or metaraminol may be used 1
  • Important: Do NOT use epinephrine, as hydroxyzine counteracts its pressor action 1
  • ECG monitoring is recommended in cases of overdose due to risk of QT prolongation and Torsade de Pointes 1

Clinical Pearls and Precautions

• When prescribing hydroxyzine:

  • Use caution in patients already taking medications known to cause hypotension 5
  • Consider lower doses in elderly patients or those with cardiovascular disease 6
  • Monitor for symptoms of orthostatic hypotension (dizziness, lightheadedness upon standing) 6

• In cases of suspected hydroxyzine-induced hypotension:

  • Perform medication review to identify potential drug interactions 6
  • Consider alternative H1-antihistamines if hydroxyzine is suspected as the cause 2
  • Document the reaction to prevent future re-exposure if an anaphylactic reaction is suspected 2

While hydroxyzine is not primarily known as an antihypertensive agent, clinicians should be aware of its potential to cause hypotension, particularly in overdose situations or in vulnerable patients with multiple risk factors for orthostatic hypotension 1, 6.