Organophosphate Poisoning and Carbamate Poisoning By Gerald F O'Malley, DO, Grand Strand Regional Medical Center; Rika O'Malley, MD, Grand Strand Medical Center Reviewed / Revised Jun 2022 | Modified Sep 2022 View Patient Education Pathophysiology Symptoms and Signs Diagnosis Treatment Key Points Organophosphates and carbamates are common insecticide ingredients that inhibit cholinesterase activity, causing acute muscarinic manifestations (eg, salivation, lacrimation, urination, diarrhea, emesis, bronchorrhea, bronchospasm, bradycardia, miosis) and some nicotinic symptoms, including muscle fasciculations and weakness.