Fexofenadine (Allegra) is Preferred Over Loratadine (Claritin) for ESRD Pruritus
For patients with End-Stage Renal Disease (ESRD) experiencing pruritus, fexofenadine (Allegra) is preferred over loratadine (Claritin) due to its better safety profile in renal impairment and non-sedating properties. 1, 2
Antihistamine Selection in ESRD
- Fexofenadine is recommended as the preferred second-generation antihistamine for ESRD patients due to its high margin of safety in subjects with renal impairment 2
- Fexofenadine is truly non-sedating even at high doses, showing no dose-related increase in sedation, which is particularly important in ESRD patients who may be more sensitive to CNS effects 2
- Loratadine should be used with caution in severe renal impairment according to British Journal of Dermatology guidelines 3
- First-generation antihistamines like diphenhydramine should be completely avoided in ESRD patients due to increased risk of sedation, falls, and potential long-term use predisposing to dementia 1, 4
Dosing Recommendations for ESRD Patients
- For fexofenadine, the FDA recommends a reduced starting dose of 60 mg once daily in patients with decreased renal function 5
- Loratadine requires cautious use in severe renal impairment but specific dose adjustments are less clearly defined 3
- Cetirizine and levocetirizine should be avoided in severe renal impairment (creatinine clearance < 10 mL/min) 3
Efficacy Considerations for Uremic Pruritus
- Antihistamines generally have limited efficacy for uremic pruritus compared to other treatments 1, 6
- The British Journal of Dermatology specifically recommends avoiding cetirizine for uremic pruritus in hemodialysis patients due to lack of effectiveness 1
- While antihistamines may not be the most effective treatment for uremic pruritus, when choosing between them, fexofenadine offers the best safety profile for ESRD patients 1, 2
Alternative Treatments to Consider
- Gabapentin (100-300 mg after dialysis three times weekly) has shown better efficacy than antihistamines for uremic pruritus 7, 6
- Topical capsaicin 0.025% cream applied four times daily has shown significant efficacy in randomized trials 7
- Broad-band UVB phototherapy is an effective treatment for many patients with uremic pruritus 7
- Sertraline has shown promise for antihistamine-refractory uremic pruritus in renal palliative care patients 8, 9
Important Considerations and Pitfalls
- Non-pharmacological approaches should not be overlooked, including optimization of dialysis adequacy (target Kt/V of around 1.6), normalization of calcium-phosphate balance, and use of emollients for dry skin 7, 1
- Long-term use of sedative antihistamines may predispose to dementia and should be avoided except in palliative care settings 7, 1
- Renal transplantation remains the only definitive treatment for uremic pruritus but is not always feasible 7
In conclusion, when choosing between Allegra and Claritin for ESRD-related pruritus, fexofenadine (Allegra) is the preferred option due to its established safety in renal impairment and non-sedating properties, though clinicians should be aware that antihistamines overall have limited efficacy for uremic pruritus compared to other treatment options.