Which of the following medications should be dosed according to total body weight (TBW), instead of lean body mass in morbidly obese patients

Succinylcholine should be dosed according to total body weight (TBW), not lean body mass. Morbidly obese patients have elevated activity of pseudocholinesterase, the enzyme responsible for the metabolism of succinylcholine. Thus, dosing by total body weight is necessary to ensure complete relaxation prior to intubation. Morphine by PCA, vecuronium, and pancuronium should be dosed according to lean body mass.