Q: Why Succinylcholine should be use with caution in Myasthenia Gravis patients?

Answer: Succinylcholine can have unpredictable effects in patients with myasthenia gravis.

Firstly, The relative lack of ACh receptors makes these patients somewhat resistant to succinylcholine

Secondly, higher doses may be required to achieve desirable effect.

Thirdly, Paralysis effect may be prolonged.

Reference:

Juel VC. Myasthenia gravis: management of myasthenic crisis and perioperative care. Semin Neurol. Mar 2004;24(1):75-81