Mecanismos envolvidos na analgesia da lidocaína por via venosa

Abstract

BACKGROUND AND OBJECTIVES: Intravenous lidocaine has been used for several indications since the decade of 1960. Its multimodal mechanism of action was the objective of this review. CONTENTS: Mechanisms of action that diverge from the classical Na+ channel blockade, the differential action of intravenous lidocaine in central sensitization, and the analgesic and cytoprotective actions, as well as the different doses of intravenous lidocaine were reviewed. CONCLUSIONS: The final analgesic action of intravenous lidocaine is a reflection of its multifactorial action. It has been suggested that its central sensitization is secondary to a peripheral anti-hyperalgic action on somatic pain and central on neuropathic pain, which result on the blockade of central hyperexcitability. The intravenous dose should not exceed the toxic plasma concentration of 5 μg.mL-1; doses smaller than 5 mg.kg -1, administered slowly (30 minutes), under monitoring, are considered safe. © Sociedade Brasileira de Anestesiologia, 2008.