NREMT Paramedic Exam 2025 – 400 Free Practice Questions to Pass the Exam

In cases of cholinergic overdose, one of the hallmark symptoms is constricted pupils, also known as miosis. This effect occurs due to the overstimulation of the parasympathetic nervous system, which is responsible for the actions mediated by acetylcholine.

Cholinergic agents, including certain medications and toxins, lead to an accumulation of acetylcholine at nerve synapses. This overactivity of the cholinergic system causes various physiological effects, including excessive stimulation of the iris sphincter muscle, resulting in the constriction of the pupils.

While increased urination can also be a symptom of cholinergic effects due to stimulation of the bladder, it is not as defining as the constricted pupils. Dry mouth is typically associated with anticholinergic overdose, where inhibition of acetylcholine leads to decreased salivation, and wheezing can occur due to bronchoconstriction but is not as specific to cholinergic overdose as miosis.