title: Safety of lidocaine-prilocaine cream application four times a day in premature neonates: a pilot study.
abstract: Although safety is established for lidocaine-prilocaine cream application to the heel once a day in neonates, it is often necessary to repeat heel lances several times a day in the clinical situation. A pilot safety study applying 0.5 g lidocaine-prilocaine cream to the heel covering an area of 5 cm2 with an occlusive dressing during 30 min four times a day was carried out. Twelve neonates (5 male, 7 female) with a gestational age of 30.1-36.3 weeks (mean 31.6 weeks) and a birth weight of 1100-2910 g (mean 1665 g) were enclosed. To establish safety, methaemoglobin levels and plasma concentrations of lidocaine, prilocaine and o-toluidine were measured until 24 h after the final application. Methaemoglobin levels were no different from baseline measurements, ranging from 0.2-1.1% and 0.1-0.7% respectively. Plasma concentrations of lidocaine and prilocaine were very low, maxima at 0.230 and 0.223 mg/l respectively. Plasma o-toluidine concentrations remained below the detection limit (0.025 mg/l).
  
  
  CONCLUSIONS
  Application of 0.5 g lidocaine-prilocaine cream to the heel under occlusion four times a day during 30 min is safe in preterm neonates. Establishing safety by measuring the methaemoglobin level by daily application is recommended.
authors.affiliation: Department of Clinical Pharmacy, University Hospital Nijmegen, The Netherlands.
authors.forename: C M
authors.initials: CM
authors.lastname: Essink-Tebbes
authors.forename: E W
authors.initials: EW
authors.lastname: Wuis
authors.forename: K D
authors.initials: KD
authors.lastname: Liem
authors.forename: R T
authors.initials: RT
authors.lastname: van Dongen
authors.forename: Y A
authors.initials: YA
authors.lastname: Hekster
mesh_terms: D019162:Anesthetics, Combined / Q000493:pharmacokinetics; D000779:Anesthetics, Local / Q000493:pharmacokinetics; D016903:Drug Monitoring; D005260:Female; D006365:Heel; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008012:Lidocaine / Q000008:administration & dosage / Q000493:pharmacokinetics; D000077442:Lidocaine, Prilocaine Drug Combination; D008297:Male; D008706:Methemoglobin / Q000378:metabolism; D009824:Ointments; D010865:Pilot Projects; D011318:Prilocaine / Q000008:administration & dosage / Q000493:pharmacokinetics
chemical_list: D019162:Anesthetics, Combined; D000779:Anesthetics, Local; D000077442:Lidocaine, Prilocaine Drug Combination; D009824:Ointments; D011318:Prilocaine; D008706:Methemoglobin; D008012:Lidocaine