Lidocaine 在局部塗抹於黏膜後被吸收,其吸收速率與吸收量視使用的濃度、給藥總量、給藥特定部位及與藥物接觸之時間長短而定。一般而言氣管內給藥及支氣管給藥之吸收速率最快。再胃腸道之吸收亦良好,然而因肝臟之生體轉化作用,在血中期未經代謝之原型相當少。
Onset of action: Single bolus dose: 45-90 seconds
Duration: 10-20 minutes
Distribution: Vd: 1.1-2.1 L/kg; alterable by many patient factors; decreased in CHF and liver disease; crosses blood-brain barrier
Protein binding: 60% to 80% to alpha1 acid glycoprotein
Metabolism: 90% hepatic; active metabolites monoethylglycinexylidide (MEGX) and glycinexylidide (GX) can accumulate and may cause CNS toxicity
Half-life elimination: Biphasic: Prolonged with congestive heart failure, liver disease, shock, severe renal disease; Initial: 7-30 minutes; Terminal: Infants, premature: 3.2 hours, Adults: 1.5-2 hours
|