Methemoglobinemia induced by lidocaine-prilocaine cream.

The Israel Medical Association journal : IMAJ (2014-05-20)
Oded Shamriz, Inbal Cohen-Glickman, Shimon Reif, Eyal Shteyer
ABSTRACT

With growing awareness of the importance of pain control in all procedures, the use of lidocaine-prilocaine cream (EMLA) for all ages is increasing. Lidocaine-prilocaine cream has been implicated as a cause of methemoglobinemia. Diagnostic clues may be oxygen-resistant cyanosis and an oxygen "saturation gap" between arterial blood saturation and pulse oximetry. Treatment with intravenous methylene blue is often effective. Since EMLA is often mistakenly considered risk-free it is routinely applied by medical staff in the emergency room. Subsequent to the case of EMLA-induced methemoglobinemia in an 8 year old girl we wish to alert the medical community to this phenomenon, and in this work review the relevant literature.

MATERIALS
Product Number
Brand
Product Description

Supelco
Lidocaine hydrochloride, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
Methylene Blue solution, for microscopy, concentrate according to Ehrlich, concentrated, aqueous solution
Sigma-Aldrich
Lidocaine, powder
Supelco
Lidocaine, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
Lidocaine hydrochloride monohydrate, solid
USP
Lidocaine, United States Pharmacopeia (USP) Reference Standard
Sigma-Aldrich
Methylene Blue solution, suitable for microbiology
Sigma-Aldrich
Lidocaine, analytical standard
Lidocaine hydrochloride, European Pharmacopoeia (EP) Reference Standard
Sigma-Aldrich
Prilocaine hydrochloride, ≥98% (TLC)
Prilocaine hydrochloride, European Pharmacopoeia (EP) Reference Standard
Lidocaine, European Pharmacopoeia (EP) Reference Standard
Sigma-Aldrich
Prilocaine hydrochloride, meets USP testing specifications