Indirect parasympathomimetics

Inhibit AchE → ↓ breakdown of ACh → ↑ ACh levels

• Neostigmine
  • Can not cross the blood-brain barrier (quaternary amine)
    • Thus cannot be used to treat atropine OD
  • Myasthenia gravis
  • Postoperative and neurogenic ileus and urinary retention
  • Postoperative reversal of neuromuscular blockade
• Pyridostigmine
  • Can not cross the blood-brain barrier (quaternary amine)
  • Typically used with glycopyrrolate, hyoscyamine, or propantheline to control side effects
  • Myasthenia gravis (longer action compared to neostigmine): improves muscle strength
• Physostigmine
  • Lipophilic
  • Can cross the blood-brain barrier (tertiary amine)
  • Atropine overdose (antidote)