Rocuronium has a high incidence of inducing pain by intravenous injection, and different methods have been used to minimize the incidence and severity of this pain. In this study, we have compared the effects of lidocaine and metoclopramide pretreatments on rocuronium injection pain.

Ninety healthy patients scheduled for general anesthesia were randomly divided into three groups; a saline group (n = 30), a lidocaine group (n = 30), and a metoclopramide group (n = 30). Each patient received 2 ml of pretreatment solution (normal saline, 2% lidocaine, or 0.5% metoclopramide) via an 18 G angiocatheter inserted in the antecubital fossa after applying an arm tourniquet inflated to 50 mmHg. The tourniquet was released 1 minute later, and this was followed by an intravenous injection of 0.6 mg/kg of rocuronium. General anesthesia then induced with thiopental sodium (5 mg/kg). The assessment of pain was made at the induction of anesthesia and in the recovery room, and the severity of pain was classified as none, mild, moderate, or severe by an observer.

The severity and incidence of pain diminished significantly in the lidocaine and metoclopramide groups compared with the saline group at the induction of anesthesia (P < 0.05), but no significant difference was observed between the lidocaine and metoclopramide groups. Similar results were obtained in the recovery room; one patient in each of the saline and metoclopramide groups had no recall regarding injection pain.

Intravenous metoclopramide pretreatment is as effective as intravenous lidocaine pretreatment for alleviating rocuronium injection pain.