Cholinergic Small Group

Question 1

How do you diagnose a MG patient by improving their muscle movement?

Answer 1

IV edrophonium

Temporarily and dramatically improve muscle movement

Question 2

How do you diagnose a MG pt by making their muscle weakness worse? What do you need to reverse this?

Answer 2

IV d-tubocurarine = competitive blocker that makes a MG pt weaker than a normal person would
Neositgmine = reversal

Question 3

What do you give a MG pt during a cholinergic crisis?

Answer 3

Atropine

Question 4

What is a cholinergic crisis? What are the symptoms?

Answer 4

Overstimulate para 
- In this example, gave anti-ACh (d-tubocurarine) causing severe muscarinic activation 
Bradycardia
Miosis
Diarrhea 
Generalized skeletal muscle weakness

Question 5

Pathophys of MG

Answer 5

Autoimmune
Abs vs skeletal muscle nACh receptors
Long term = complement lysis of nerve terminals –> low ACH receptor # –> destroy endplates

Question 6

What is a myasthenic crisis? What is your biggest concern during one of these?

Answer 6

Insufficient nAChR activation

Breathing - intubate

Question 7

What is first line treatment for MG?

Answer 7

Neostigmine
OR
Pyridostigmine

Question 8

Which drug do you also give MG pts with anti-ChEs to prevent muscarinic effects?

Answer 8

Atropine - give with or before

Question 9

What changes to muscarinic receptors occur with chronic atropine use?

Answer 9

Down-regulate mR

No need to give atropine eventually

Question 10

What do you give MG pts if neostigmine and pyriostygmine are ineffective?

Answer 10

Ambenonium (non-carbamate anti-ChE)

Question 11

What other supportive treatments are useful for MG pts?

Answer 11

Prednisolone - immune suppression
Thymectomy
Plasmapheresis