Differentiate between the commonly employed non-depolarizing muscle relaxants.
All nondepolarizing muscle relaxants decrease striated muscle strength by competitive inhibition of postsynaptic acetylcholine receptors at the neuromuscular junction. Some muscle relaxants affect prejunctional acetylcholine receptors as well. Clinically important parameters that distinguish nondepolarizing muscle relaxants from one another include onset times, elimination times, routes of elimination, and potency (Table 24.1). Rocuronium is unique among the nondepolarizing muscle relaxants for its rapid onset of action.
Intubating doses of 2–3 times the effective dose that produces 95% twitch height depression (ED95) may provide intubating conditions in 60–90 seconds, which approaches but does not equal the onset time for succinylcholine.