This resource includes information about organophosphate poisoning, acetylcholine, acetylcholinesterase (AChE), direct-acting agonists, indirect agonists, AchE inhibitors: reversible versus irreversible, inhibition by organophosphate: “Aging”, pharmacokinetics of organophosphates, effects of acute O/P overdose, treatment, therapeutic use of AchE inhibitors and summary of key points.