<p>Bupivacaine binds to the intracellular portion of voltage-gated sodium channels and blocks sodium influx into nerve cells, which prevents depolarization. Without depolarization, no initiation or conduction of a pain signal can occur.<br />
<br />
The rate of systemic absorption of bupivacaine and other local anesthetics is dependent upon the dose and concentration of drug administered, the route of administration, the vascularity of the administration site, and the presence or absence of epinephrine in the preparation.</p>

<ul>
	<li>Onset of action (route and dose-dependent): 1-17 min</li>
	<li>Duration of action (route and dose-dependent): 2-9 hr</li>
	<li>Half life: neonates, 8.1 hr, adults: 2.7 hr</li>
	<li>Time to peak plasma concentration (for peripheral, epidural, or caudal block): 30-45 min</li>
	<li>Protein binding: about 95%</li>
	<li>Metabolism: hepatic</li>
	<li>Excretion: renal (6% unchanged)</li>
</ul>