TAC, EMLA, LET…Zingo? Emergency physicians and parents have long wished for the perfect local anesthetic for pediatric patients, something painless, safe, fast, and 100% effective (and don’t forget cheap). Has the perfect one arrived? Probably not perfect, but if it lives up to its promise, Zingo will be much closer to the ideal than anything we have now. Our pediatric patients can expect reduced pain and the safety profile of lidocaine, but delivered faster and with less effort than conventionally injected local anesthetics.
What is Zingo?
Zingo is a gas powered needle-free injection system that delivers lidocaine hydrochloride monohydrate powder intradermally. Unlike available topicals such as EMLA, LET and LMX, which need at least 20 to 30 minutes, this system takes effect in one to three minutes. Dr. William Zempsky, principal investigator in the Zingo study, comments, “It really didn’t interrupt the flow of the procedure at all. You deliver the drug, you turn around, you get your tourniquet, you put it on and you put your needle in. There’s nothing like that on the market currently.”
Dr. Zempsky is an associate professor of Pediatrics and Emergency Medicine at the University of Connecticut and associate director of Connecticut Children’s Medical Center Pain Relief Program. He spent 10 years in the ED and has been doing topical anesthetic research for nearly 15 years. “I got interested during my fellowship because there was nothing that worked quickly that could be used for IVs, venipunctures, lacerations, etc… Every time I do a study I’ve been looking for something that really is going to be the answer. I think this may be it.”
One study showed Zingo scored adjusted mean of 1.77 on the Wong-Baker Faces pain scale (0–5) vs. 2.10 for placebo. A second study using the same scale found 1.38 for Zingo vs. 1.77 for placebo. It’s too early in the process for studies against existing topicals. Although Dr. Zempsky expects such studies, he is unsure what they will mean. “It really has no comparison group because of the speed with which it works.”
One potential sticking point could be the noise associated with the device—said to be like a popping baloon at the moment of actuation—but Dr. Zempsky says that at his site, this hasn’t been a problem. “We studied this in 450 plus kids. We really had no issues with the sound, no issues with acceptability with any patient. [As for] the comfort level with drug delivery, the pain scores were approaching zero. The device works very quickly so there wasn’t really any issue with it at all.”
The side effects are those related to the lidocaine itself and local reactions at the site of application: petechiae, edema, erythema, itching. The dose is very small, only 0.5 milligrams. There’s none of the pain from the lidocaine itself, or the need to buffer that’s associated with standard lidocaine injections. Since this is a powdered lidocaine, Dr. Zempsky says, “There’s no liquid, so there’s no burning.”
Zingo is approved for children from 3 to 18 years of age for phlebotomy and IV placement. Whether or when Anesiva, the manufacturer, will seek to extend the age range and indications is not yet known. There is obvious potential for use in certain adults, or for other procedures in children such as lumbar puncture. Given such a small dose of lidocaine, we can expect consideration of Zingo for children under three years old as well.
A potential downside is the expense of the system, as the drug is delivered via a single-use helium powered pressure injector. While the pricing hasn’t been announced as of this writing, Dr. Zempsky expects it will be competitive with other topical formulations. As with LET and EMLA, Zingo is not recommended for mucous membranes. In contrast to those topical anesthetics, Zingo is approved only for intact skin. Dr. Zempsky notes that the area anesthetized is fairly small, and any laceration that small is likely amenable to Dermabond. His ED, like many others, has nursing protocols to apply LET in triage to children who may need suturing, IVs, or other minor procedures. Zingo won’t put those protocols on the shelf, but should markedly reduce the number of indications.
Anesiva will announce availability and pricing shortly. It is expected to be on the market some time in 2008. If Zingo holds up to its promise, parents, children, and EPs everywhere will be very grateful.