Hydroxyzine Carries Significant Long-Term Cognitive Impairment Risk and Should Be Avoided in Older Adults
Hydroxyzine poses a substantial risk for cognitive impairment, particularly with long-term use, and is explicitly identified as a potentially inappropriate medication in older adults due to its anticholinergic properties that cause CNS impairment including delirium, slowed comprehension, and sedation. 1, 2
Evidence from Guidelines
The 2019 AGS Beers Criteria and 2021 Mayo Clinic polypharmacy guidelines both classify hydroxyzine as an "old antihistamine" with anticholinergic properties that should be avoided in older adults 1, 2. The mechanism is clear: broad muscarinic receptor blockade leads to:
- CNS impairment: delirium and slowed comprehension
- Cognitive dysfunction: sedation and impaired processing
- Falls risk: from sedation and impaired mobility
- Vision impairment, urinary retention, and constipation 2
The FDA label reinforces these concerns, explicitly warning that "sedating drugs may cause confusion and over sedation in the elderly" and recommends starting elderly patients on low doses with close observation 3.
Quantified Cognitive Risk
The strongest research evidence demonstrates:
A meta-analysis of 621,548 participants found that anticholinergic drug use (including hydroxyzine) is associated with:
- 20% increased risk of incident dementia with any use (OR 1.20,95% CI 1.09-1.32)
- 50% increased risk with long-term use (≥365 days) (OR 1.50,95% CI 1.22-1.85)
- Significant cognitive decline (SMD 0.15,95% CI 0.09-0.21) 4
Acute Risks in Emergency Settings
Even single-dose administration carries risk. A 2025 study of geriatric ED patients found:
- 15% experienced adverse drug effects from first-generation antihistamines
- Delirium occurred in 7.7% of encounters
- Patients ≥85 years had 5.5-fold increased risk (RR 5.5,95% CI 2.7-11.4)
- Those with pre-existing cognitive impairment had 3.1-fold increased risk (RR 3.1,95% CI 1.8-5.4)
- Multiple doses increased risk 1.9-fold 5
Pediatric Concerns
Long-term neurodevelopmental effects extend beyond the elderly. Repeat hydroxyzine prescriptions in preschool children showed increased odds of:
- Tic disorders (OR 1.55)
- Anxiety disorders (OR 1.34)
- Conduct disturbances (OR 1.34) 6
Clinical Algorithm for Decision-Making
When considering hydroxyzine:
- Age ≥65 years: Avoid entirely—use alternative non-anticholinergic agents
- Age ≥85 years or pre-existing cognitive impairment: Absolute contraindication
- Younger adults requiring short-term use (<90 days): May consider with caution
- Any patient on chronic therapy: Deprescribe using taper protocols 2
Critical Pitfalls to Avoid
- Do not use hydroxyzine for anxiety in older adults—the 2025 ED study found 60% of hydroxyzine doses were inappropriately prescribed for anxiety 5
- Do not assume single doses are safe in vulnerable populations—even one dose carries 7.7% delirium risk in older adults 5
- Do not continue long-term without reassessment—cognitive effects accumulate with duration 4
Safer Alternatives
For conditions where hydroxyzine might be considered:
- Anxiety: Cognitive behavioral therapy, SSRIs (avoid benzodiazepines which carry similar risks) 2
- Pruritus: Non-sedating second-generation antihistamines (cetirizine, loratadine)
- Sleep: Non-pharmacological interventions first; if medication needed, consider alternatives with lower anticholinergic burden 7
The evidence is clear: hydroxyzine's anticholinergic properties create unacceptable cognitive risk, particularly in older adults, those with pre-existing cognitive impairment, and with prolonged use. The 50% increased dementia risk with long-term use demands immediate deprescribing efforts in current users and avoidance in new prescriptions for vulnerable populations.