Final answer:
Haloperidol should be avoided in dementia-related psychosis, especialmente in Parkinson's disease dementia or Lewy body dementia due to exacerbation of motor symptoms.
Step-by-step explanation:
Typical antipsychotics, like haloperidol (Haldol), should not be used in patients with dementia-related psychosis, especially those with Parkinson's disease dementia or Lewy body dementia. These conditions involve underlying neurodegenerative processes that affect the dopaminergic system.
Since typical antipsychotics block dopamine receptors, their use can exacerbate motor control issues, leading to serious side effects such as worsening of Parkinsonian symptoms. These side effects are of particular concern because patients with Parkinson's disease or Lewy body dementia already have compromised motor systems due to reduced dopamine levels in the brain.