Szenohradsky, J et al. Anesth 2000; 92: 708-14.

Reviewed by: R. Prasad, MD

Conclusions
-Edroph may displace miva from tissue temporarily (causing transiently increased serum levels)
-Neostig decreases plasma cholinesterase activity, decreasing miva metabolism. But, this effect is overcome by increases in [ACh], because:
-Both agents facilitate recovery, but not much (2-3 min)
-Placebo group recovered more slowly after 2nd infusion, suggesting persistent weakness (perhaps from accumulation of cis-cis isomer)

Methods
-20 pts; 2 excluded from analysis
-GA ox/nitrous 60%, iso 0.8%ET
-miva infused for 40min, then discontinued for 15min, then resumed for 40min
-pts randomized to receive reversal (0.5 mg/kg edroph, or 50 mcg/kg neostig) or saline, + atropine 1mg
-plasma sampled for active miva levels, twitch tensions recorded

Results
-after end of 2nd infusion, [miva] higher than after 1st infusion at 2min with edroph, and 2, 4, and 7min with neostig. That is, both reversal agents slow mivacurium metabolism temporarily (edroph ~2 min, neostig ~7min)
-reversal (twitch tension recovery) faster after 2nd infusion (i.e., after reversal) for both drugs