Hydroxyzine Dosing in ESRD
For patients with end-stage renal disease, hydroxyzine should be dose-reduced (typically starting at 12.5-25 mg) and administered after hemodialysis sessions on dialysis days, with close monitoring for excessive sedation and anticholinergic effects. 1, 2
Rationale for Dose Reduction
Hydroxyzine undergoes significant renal excretion, and the extent of renal elimination makes dose adjustment critical in ESRD patients to prevent drug accumulation and toxicity. 2
Standard adult doses (50 mg or higher) should not be used without reduction, as ESRD significantly impairs drug clearance and increases the risk of adverse effects including excessive CNS depression, falls, and anticholinergic toxicity. 1
The FDA label specifically emphasizes caution in patients with decreased renal function, noting that elderly patients (who comprise a large proportion of ESRD patients) are more likely to have impaired renal clearance and should start on low doses. 2
Timing of Administration
Administer hydroxyzine after hemodialysis sessions on dialysis days to prevent premature drug removal and ensure adequate therapeutic levels. 1
Avoid pre-dialysis administration, which would result in subtherapeutic drug levels due to dialytic clearance. 1
This timing principle is consistent with general medication management in hemodialysis patients to optimize drug exposure. 3, 1
Critical Monitoring Parameters
Monitor closely for orthostatic hypotension and falls, particularly problematic in ESRD patients who are often on concurrent antihypertensives and diuretics. 1
Watch for excessive sedation and CNS depression, as ESRD patients have altered nonrenal drug clearance pathways that can lead to increased drug exposure. 4
Reassess clinical response within 48-72 hours of initiation and adjust dosing if there is excessive sedation or inadequate symptom control. 1
Be vigilant for QT prolongation, especially given that ESRD patients often have electrolyte imbalances (a risk factor for QT prolongation and Torsade de Pointes). 2
Drug Interaction Considerations
Do not combine with other anticholinergic or sedating medications without careful consideration of additive CNS depression and fall risk. 1
Reduce dosages of concomitant CNS depressants (narcotics, non-narcotic analgesics, barbiturates) when used with hydroxyzine due to potentiating effects. 2
Exercise caution with medications that prolong the QT interval (Class 1A and III antiarrhythmics, certain antipsychotics, antidepressants, and antibiotics), as ESRD patients may have multiple risk factors for arrhythmias. 2
Common Pitfalls to Avoid
Never use standard adult dosing without reduction in ESRD patients, as this dramatically increases toxicity risk. 1, 2
Do not administer before dialysis sessions, which removes the drug prematurely. 1
Avoid overlooking the increased bleeding risk if combining with NSAIDs, as uremic patients have baseline platelet dysfunction. 5
Do not ignore the higher risk of adverse drug reactions in ESRD patients, who typically take multiple medications and have altered pharmacokinetics affecting both renal and nonrenal clearance pathways. 6, 4