NREMT Paramedic Practice

Which substances are categorized as cholinergics?

1. Antidepressants

2. Pesticides

3. Skeletal muscle relaxers

4. Antihistamines

The correct answer is: Pesticides

Cholinergics are substances that promote the action of acetylcholine, a key neurotransmitter in the nervous system. Pesticides, particularly organophosphate and carbamate compounds, inhibit the enzyme acetylcholinesterase, which normally breaks down acetylcholine. This inhibition leads to an accumulation of acetylcholine in the synapses, thereby enhancing cholinergic signaling. This property makes certain pesticides act as cholinergic agents, affecting both insects and potentially humans if exposed. In contrast, antidepressants, skeletal muscle relaxers, and antihistamines do not primarily exert their effects through cholinergic mechanisms. Antidepressants may influence serotonin and norepinephrine pathways, skeletal muscle relaxers target neuromuscular junctions, and antihistamines are primarily anticholinergic, blocking the action of acetylcholine at histamine receptors. Understanding the action of these substances helps in recognizing the specific role cholinergics play in pharmacology and how they can affect both therapeutic and toxicological outcomes.