What anticholinergic (anticholinergic) medications should be avoided in patients with Parkinson's disease?

From the Guidelines

Patients with Parkinson's disease should avoid anticholinergic medications, such as antihistamines and muscle relaxants, as they can worsen cognitive function and exacerbate Parkinson's symptoms. When considering medication management for patients with Parkinson's disease, it is essential to prioritize those that minimize adverse effects on cognitive function and motor symptoms. According to a recent study on polypharmacy management in older patients 1, anticholinergic medications, including old antihistamines like diphenhydramine and hydroxyzine, pose significant risks to older adults, such as CNS impairment, delirium, and slowed comprehension. Some key anticholinergic medications to avoid in Parkinson's disease include:

• Antihistamines: diphenhydramine (Benadryl) and hydroxyzine
• Muscle relaxants: cyclobenzaprine and metaxalone
• Overactive bladder medications: oxybutynin (Ditropan) These medications can cause a range of adverse effects, including dry mouth, constipation, urinary retention, and blurred vision, which can further compromise the quality of life for patients with Parkinson's disease. It is crucial for patients with Parkinson's disease to consult their neurologist before discontinuing any medications, as some may be prescribed specifically for certain Parkinson's symptoms 1.

From the Research

Anticoagulant Medications to Avoid in Parkinson's Disease

• The following anticoagulant medications may increase the risk of intracranial hemorrhage (ICH) in patients with Parkinson's disease:
  • Rivaroxaban: may increase the risk of ICH by 41% compared to vitamin K antagonists (VKAs) 2
  • Apixaban: may have a similar risk of ICH compared to aspirin, but may increase the risk of nonmajor bleeding 2, 3
  • Edoxaban: may have a similar risk of ICH compared to low-molecular-weight heparins (LMWHs) 2
• Patients with Parkinson's disease taking direct oral anticoagulants (DOACs) with aspirin may have a higher risk of bleeding compared to those taking warfarin with aspirin 3
• The use of CNS-active potentially inappropriate medications (PIMs) may be reduced after hospitalization for injury in older adults with Parkinson's disease, but the use of PIMs that reduce bone mineral density may not be affected 4

Medications to Use with Caution

• Cholinesterase inhibitors, such as rivastigmine or donepezil, may reduce the rate of falls in patients with Parkinson's disease, but may also increase the risk of non-fall-related adverse events 5
• Dopamine-based therapies, such as carbidopa-levodopa, may help initial motor symptoms in patients with Parkinson's disease, but may not be effective for nonmotor symptoms 6

Further Research Needed

• More research is needed to determine the relative impact of different types of exercise and different levels of supervision on falls in patients with Parkinson's disease 5
• Further studies are required to increase the certainty of the effects of medication and to explore falls prevention education interventions in patients with Parkinson's disease 5