ABSTRACT. Objectives. The purpose of this study was to determine the optimal configuration of an investigational, single-use, needle-free, drug system (ALGRX 3268) that delivers powdered lidocaine into the epidermis for the rapid production of local anesthesia among pediatric subjects undergoing venipuncture.Methods. Children 3 to 18 years of age were randomly allocated to receive 1 of 3 treatments, ie, (1) placebo, (2) a system configured to deliver 0.25 mg of lidocaine, or (3) a system configured to deliver 0.5 mg of lidocaine, at the antecubital fossa 2 to 3 minutes before venipuncture. Three age groups were included, ie, 3 to 7 years, 8 to 12 years, and 13 to 18 years. Two sets of pain rating scales were used, the Faces Pain Scale-Revised for the youngest age stratum and a visual analog scale for the oldest age stratum. Children in the middle age stratum used both scales.Results. One-hundred forty-four subjects completed the study. For all ages combined, there was a statistically significant and clinically meaningful reduction in pain scores for subjects who received 0.5 mg of lidocaine, compared with placebo. The reduction in pain after 0.25 mg of lidocaine did not achieve statistical significance.Conclusions. Both active configurations were safe and well tolerated by pediatric subjects undergoing venipuncture at the antecubital fossa. ALGRX 3268 at 0.5 mg, administered 2 to 3 minutes before venipuncture, produced significantly lower pain scores, compared with placebo. [5][6][7][8][9] However, a period of 30 to 90 minutes, depending on the product and the procedure, may be required between application and the onset of effect, limiting the usefulness of these products in busy health care settings and for emergency department applications. [9][10][11] The delivery of lidocaine to the skin through iontophoresis has also been investigated among children undergoing venipuncture or intravenous catheter insertion. 12,13 Iontophoretic lidocaine systems feature a controller and disposable, drug-saturated electrodes and use the application of an electric current to carry ionized lidocaine through the skin. 13 Lidocaine iontophoresis has been shown to be more effective than placebo in reducing the pain of venipuncture and to be comparable to EMLA for intravenous catheter placement. 12,13 However, studies indicate that lidocaine iontophoresis requires up to 15 minutes for onset of effect. 14 This study was undertaken to evaluate an investigational, needle-free, single-use, prefilled, disposable system (ALGRX 3268; AlgoRx Pharmaceuticals Inc, Secaucus, NJ) capable of delivering fine, dry, powdered lidocaine into the epidermis for the rapid production (within 1-3 minutes) of local anesthesia before venipuncture. The system is placed against the skin at the site of venipuncture and is triggered simply by pressing of the actuator button (Fig 1). Pressurized, medical-grade, helium gas within the system accelerates lidocaine particles to velocities sufficient to penetrate the outer skin layers and produce local anesthesia. ...