Does hydroxyzine (an antihistamine) exacerbate Parkinson's disease symptoms?

Hydroxyzine Can Worsen Parkinson's Disease Symptoms

Hydroxyzine should be avoided in patients with Parkinson's disease due to its anticholinergic properties that can exacerbate parkinsonian symptoms. 1

Mechanism of Concern

• Hydroxyzine is a first-generation antihistamine with significant anticholinergic properties 1
• Anticholinergic medications can induce or worsen symptoms of Parkinson's disease, including:
  • Worsening of tremor and rigidity 1
  • Increased risk of cognitive impairment 2
  • Potential to exacerbate existing motor dysfunction 3

Impact on Parkinson's Disease

• Antidopaminergic agents, including those with anticholinergic properties like hydroxyzine, can induce symptoms resembling Parkinson's disease, including bradykinesia, tremors, and rigidity 1
• The anticholinergic burden in Parkinson's disease patients is significant and can worsen both motor and non-motor symptoms 2
• Anticholinergic medications can counteract the therapeutic effects of medications used to treat Parkinson's disease, particularly cholinesterase inhibitors that may be prescribed for cognitive symptoms 2

Clinical Considerations

• First-generation antihistamines like hydroxyzine are associated with:

  • Significant sedation and performance impairment 1
  • Anticholinergic side effects that can worsen cognitive function 1
  • Potential to increase risk of falls, which is already elevated in Parkinson's patients 1

• Older adults, including many Parkinson's patients, are more sensitive to psychomotor impairment from first-generation antihistamines and have increased risk for complications such as falls 1

Alternative Options

• If antihistamine therapy is necessary for a patient with Parkinson's disease:

  • Second-generation (non-sedating) antihistamines with minimal anticholinergic effects are preferred 1
  • Loratadine or cetirizine may be better options as they have fewer central nervous system and anticholinergic effects 1

• For sleep issues in Parkinson's patients (which hydroxyzine is sometimes prescribed for):

  • Melatonin may be considered as it has minimal side effects and has shown benefit in REM sleep behavior disorder, which is common in Parkinson's disease 1
  • Clonazepam may be used with caution for REM sleep behavior disorder in Parkinson's patients 1

Common Pitfalls to Avoid

• Assuming that hydroxyzine's sedative properties make it a good choice for sleep in Parkinson's patients - the anticholinergic burden outweighs potential benefits 1
• Overlooking that anticholinergic medications contribute significantly to cognitive decline in Parkinson's patients 2
• Failing to recognize that medications used for non-motor symptoms (like hydroxyzine for anxiety or sleep) can worsen motor symptoms of Parkinson's disease 2