Pang et al and Mok et al, has demonstrated that 40mg of meperidine is equally effective as 60mg of lidocaine to reduce pain associated to propofol.This is similar to an Egyptian study, which documented equal efficacy of premedicating with 0.5mg/kg of Meperidine as with 1mg/kg of lidocaine.This phenomenon can be attributed to meperidine’s anesthetic effect, that could be related to an structure similarity to cocaine and tetracaine.Also, butorfanol an opioid agonist-antagonist had demonstrated to reduce propofol injection pain as well.
Asimismo, el butorfanol un agonista-antagonista opioide también ha demostrado reducir el dolor asociado a propofol.