Overstimulation of muscarinic sites in the central nervous system can cause confusion, ataxia, slurred speech, Cheyne-Stokes respiration, convulsions, coma, and central respiratory
[path.upmc.edu]
In higher doses, people may suffer from vomiting, diarrhea, abdominal cramps, dizziness, eye pain, blurred vision, slurred speech, loss of reflexes, twitching, tremors of
[pbs.org]