What is the appropriate dose of hydroxyzine for a 73-year-old patient with impaired renal function (Creatinine Clearance of 60)?

Hydroxyzine Dosing in a 73-Year-Old Patient with Renal Impairment

For a 73-year-old patient with a creatinine clearance of 60 mL/min, the hydroxyzine dose should be reduced to 25-50 mg every 6 hours as needed, rather than the standard 50-100 mg dosing, due to increased risk of adverse effects in elderly patients with mild renal impairment. 1, 2

Rationale for Dose Adjustment

• Hydroxyzine requires dose adjustment in elderly patients due to:

  • Age-related changes in drug metabolism 2
  • Increased sensitivity to CNS depressant effects 2
  • Risk of QT prolongation, which is higher in elderly patients 2

• For patients with mild renal impairment (CrCl 60 mL/min):

  • While specific renal dosing guidelines for hydroxyzine are limited, the FDA label recommends starting at the low end of the dosing range for elderly patients 2
  • The British Journal of Dermatology guidelines recommend reducing the dose of hydroxyzine by 50% in patients with moderate renal impairment 1

Specific Dosing Recommendations

• Initial dosing:

  • Start with 25 mg every 6 hours as needed 1, 2
  • Maximum daily dose should not exceed 200 mg in elderly patients 2

• Dose titration:

  • Increase to 50 mg every 6 hours only if necessary for symptom control 1
  • Monitor closely for sedation, confusion, and cardiovascular effects 2

Monitoring Parameters

• Assess for excessive sedation and confusion, which are more common in elderly patients 2
• Monitor for QT prolongation, especially if the patient is on other medications that can prolong QT interval 2
• Evaluate for signs of anticholinergic effects (dry mouth, urinary retention, constipation) 2

Important Precautions

• Hydroxyzine should be used with caution in patients with:

  • Risk factors for QT prolongation 2
  • Concomitant use of other CNS depressants 2
  • History of cardiovascular disease 2

• The FDA label specifically warns that elderly patients should be started on low doses and observed closely due to:

  • Greater frequency of decreased hepatic, renal, or cardiac function 2
  • Higher risk of concomitant disease or drug therapy interactions 2
  • Increased risk of confusion and oversedation 2

Common Pitfalls to Avoid

• Avoid using standard adult doses in elderly patients, even with only mild renal impairment 2
• Do not combine with other medications known to prolong QT interval without careful consideration 2
• Be aware that sedating effects may be more pronounced in elderly patients, increasing fall risk 2
• Remember that creatinine clearance may overestimate actual renal function in elderly patients 3