Learning Objective
Identify major AChE inhibitors, their duration, CNS penetration, and clinical uses.
Key Drugs and Properties
| Drug | Characteristics | Clinical Uses |
|---|---|---|
| Edrophonium | Short-acting | Diagnosis of myasthenia gravis |
| Physostigmine | Tertiary amine (enters CNS) | Antidote for atropine overdose |
| Neostigmine, Pyridostigmine | Quaternary amines (no CNS entry) | Ileus, urinary retention, myasthenia gravis, reversal of nondepolarizing NM blockers |
| Donepezil, Rivastigmine | Lipid-soluble (CNS entry) | Alzheimer disease |
| Organophosphates | Lipid-soluble, irreversible | Insecticides (malathion, parathion), nerve gas (sarin) |
Activity
High-Yield Notes
- Short-acting: Edrophonium → rapid onset, useful for diagnostic testing.
- CNS entry: Tertiary amines (physostigmine) and lipid-soluble drugs (donepezil, rivastigmine) cross the BBB.
- Quaternary amines (neostigmine, pyridostigmine) act peripherally only.
- Organophosphates: irreversible AChE inhibitors → cholinergic toxicity (DUMBBELSS).
