Hydroxyzine for Itching
Hydroxyzine is effective for treating itching in specific contexts—particularly for nighttime pruritus relief due to its sedative properties—but should be used cautiously and only short-term or in palliative settings, as long-term use may predispose to dementia in elderly patients. 1
When Hydroxyzine Is Appropriate
For nighttime pruritus relief: Hydroxyzine (25-50 mg daily) may be considered based on its sedative properties in patients who suffer from pruritus during nighttime hours, particularly in the context of anticancer therapy-induced itching 1. This first-generation antihistamine works through both antihistaminic and sedative mechanisms to break the itch-scratch cycle during sleep 2.
Short-term or palliative use only: The British Association of Dermatologists explicitly states that sedative antihistamines like hydroxyzine are recommended in generalized pruritus of unknown origin only in the short-term or palliative setting (Strength of recommendation D) 1. This is a critical limitation that must guide prescribing decisions.
Important Safety Concerns
Avoid in elderly patients for chronic use: Long-term sedative antihistamines may predispose to dementia and should be avoided in elderly patients, except in palliative care (Strength of recommendation B) 1. For elderly patients with pruritus, sedative antihistamines should not be prescribed (Strength of recommendation C) 1.
Risk of worsening dermatitis: Hydroxyzine can paradoxically worsen contact dermatitis in patients with sensitivities to ethylenediamines or phenothiazines due to cross-reactivity 3. This is a rare but important pitfall to recognize—if a patient's pruritus worsens despite hydroxyzine use, consider discontinuing the medication and evaluating for contact sensitivity.
Preferred Alternatives
Non-sedating antihistamines are preferred for daytime use: Second-generation antihistamines such as loratadine (10 mg daily) or fexofenadine (180 mg daily) should be the first choice for systemic therapy during daytime hours 1. These provide antipruritic effects without sedation or cognitive impairment 1.
Cetirizine as a middle ground: Cetirizine (10 mg orally) offers mildly sedative properties with relatively rapid onset of action and may be considered as an intermediate option 1.
Evidence Quality Considerations
The evidence supporting hydroxyzine for pruritus is generally of low quality, derived primarily from case series and expert opinion rather than robust clinical trials 1. The sedative effects are well-established, but the specific antipruritic efficacy beyond sedation remains unclear 2, 4.
Key clinical algorithm: