Final answer:
Anticholinergic poisoning from substances like diphenhydramine or tricyclic antidepressants (TCAs) can cause symptoms such as dry mouth, blurred vision, increased heart rate, confusion, and hallucinations.
Step-by-step explanation:
When someone experiences anticholinergic poisoning from substances like diphenhydramine or tricyclic antidepressants (TCAs), they may exhibit various clinical manifestations and symptoms. These can include dry mouth, blurred vision, urinary retention, constipation, increased heart rate, confusion, and hallucinations. In severe cases, individuals may develop seizures, delirium, or even coma.