A lidocaine/metoclopramide combination decreases pain on injection of propofol

Injection pain is a well-known adverse effect of propofol which distresses patients. Lidocaine pretreatment is the most popular method for reducing this pain but this drug cannot entirely eliminate the problem. The purpose of this study was to examine the analgesic effect of lidocaine/metoclopramide combination, compared with lidocaine alone, during propofol injection.

In a randomized, double-blind, placebo-controlled trial, 90 patients, 40 males and 50 females, scheduled for elective plastic surgery received either lidocaine 20 mg plus metoclopramide 10 mg iv, lidocaine 20 mg iv, or placebo (saline); (n = 30 in each), with venous occlusion for one minute, followed by administration of propofol 0.5 mg.kg(-1) into a dorsal hand vein. Pain was assessed on a four-point scale (0 = none, 1 = mild, 2 = moderate, 3 = severe) during propofol injection.

25 patients (83%) complained of pain in the placebo group, compared with 12 (40%) in the lidocaine group (P < 0.05) and three (10%) in the combination group (P < 0.05). Pain score (median) was less in the lidocaine (0) and combination (0) groups than in the placebo group (2); (P < 0.05). The difference in the incidence of pain between the combination and lidocaine groups was significant (P < 0.05).

A lidocaine/metoclopramide combination is more effective than lidocaine alone for reducing pain on injection of propofol in a peripheral vein.