Phase II blocker is: (DNB June 09)
a. Phase II block (dual block) is a prolonged block due to excessive dose of succinylcholine (> 5 mg/kg or > 500 mg).
b. By repeated doses of succinylcholine there is continuous stimulation of receptors which undergoes structural changes and become non sensitive to acetylcholine.
c. Repeated stimulation can also lead to calcium mediated injury to muscle end plate.