What are clinical signs due to organophosphates and carbamates insecticides?

• A. Muscarinic signs (SLUD; parasympathetic stimulation), nicotinic (neuromuscular), and CNS
• B. Only respiratory signs
• C. Only GI signs
• D. Only dermatologic signs

Answer: (A)

These insecticides cause cholinergic toxicosis by inhibiting acetylcholinesterase, so acetylcholine accumulates at all cholinergic synapses. That overactivity affects three broad pathways: muscarinic receptors (parasympathetic stimulation) producing SLUD signs—salivation, lacrimation, urination, defecation—with bronchorrhea, bronchospasm, miosis, and bradycardia; nicotinic receptors at the neuromuscular junction causing muscle fasciculations, weakness, and in severe cases paralysis; and central nervous system effects such as agitation, ataxia, or seizures. Because all three systems can be involved, the clinical picture includes a combination of muscarinic, nicotinic, and CNS signs, which is why this option best captures the range of effects seen with organophosphate and carbamate poisoning.