Plasma concentrations of lignocaine and prilocaine after a 24-h application of analgesic cream (EMLA) to leg ulcers.

Abstract

BACKGROUND:

Although the lignocaine (lidocaine)-prilocaine cream EMLA has been extensively studied for the relief of acute treatment-related pain from sharp leg ulcer debridement, no data exist on systemic absorption from prolonged application in patients with chronically painful ulcers.

OBJECTIVES:

To study the plasma concentrations of lignocaine and prilocaine resulting from prolonged application of EMLA to leg ulcers.

METHODS:

A single 24-h application of 5-10 g (median 6.75) of EMLA was given to 10 patients with painful leg ulcers measuring 50-100 cm2. Venous blood samples, drawn between 0.5 and 27 h after cream application, were analysed by gas chromatography using a nitrogen-sensitive detector.

RESULTS:

The peak plasma levels were in the range 185-705 ng mL(-1) and 62-277 ng mL(-1) for lignocaine and prilocaine, respectively, and were observed 2-4 h (in one patient 6-8 h) after application. The peak plasma concentration of lignocaine, but not of prilocaine, increased significantly with increasing dose. The cream was well tolerated by the patients.

CONCLUSIONS:

The results indicate that a 24-h application of 5-10 g EMLA results in peak plasma concentrations of the two local anaesthetics, which combined are less than one-fifth of those associated with toxic reactions. The analgesic efficacy of EMLA for the relief of chronic ulcer pain deserves further study.

• Authors: B Stymne, S Lillieborg
• Journal: The British journal of dermatology (Br J Dermatol) Vol. 145 Issue 4 Pg. 530-4 (Oct 2001) ISSN: 0007-0963 [Print] England
• PMID: 11703277 (Publication Type: Clinical Trial, Journal Article)

Chemical References

• Anesthetics, Combined
• Anesthetics, Local
• Lidocaine, Prilocaine Drug Combination
• Ointments
• Prilocaine
• Lidocaine

Topics

• Aged
• Aged, 80 and over
• Anesthetics, Combined (administration & dosage, blood, therapeutic use)
• Anesthetics, Local (administration & dosage, blood, therapeutic use)
• Chronic Disease
• Dose-Response Relationship, Drug
• Female
• Humans
• Leg Ulcer (blood, drug therapy)
• Lidocaine (administration & dosage, blood, therapeutic use)
• Lidocaine, Prilocaine Drug Combination
• Male
• Ointments
• Prilocaine (administration & dosage, blood, therapeutic use)
• Regression Analysis