Lidocaine dosing

Various types of immunodepressant effects of local anesthetics can be detected by laboratory testing, although they may have no clinical significance. Lidocaine dose-dependently inhibits EA rosetting by human lymphocytes. In vitro depression of human leukocyte random motility and phagocytosis has also been reported (SED-11, 220) (41). 

Six patients with symptomatic cardiac arrhythmias took part in a two-phase study. Initially, lidocaine 1 mg/kg was given intravenously over 2 minutes. In phase I, loading doses of amiodarone 500 mg daily for 6 days were given, followed by the same lidocaine dose. After 19 to 21 days, when the total cumulative amiodarone dose was 13 g, the same lidocaine dose was given again (phase II). The lidocaine AUC increased by about 20% and the systemic clearance decreased by about 20%. The elimination half-life and distribution volume at steady-state were unchanged. The pharmacokinetic parameters of lidocaine in phase II were the same as those in phase I, indicating that the interaction occurs early in... 

Klein JA. Tumescent technique for regional anesthesia permits lidocaine doses of 35 mg/kg for liposuction. J Dermatol Surg Oncol 1990 16(3) 248-63. 

Drug-drug interaction The possible drug interaction between lidocaine and flecainide, both of which are anti-arrhythmics (lidocaine type IB and flecainide type 1C) could be contributing to CNS toxicity after a normal lidocaine dose [40 ]. 

Tocainide is rapidly and well absorbed from the GI tract and undergoes very fitde hepatic first-pass metabolism. Unlike lidocaine which is - 30% bioavailable, tocainide s availability approaches 100% of the administered dose. Eood delays absorption and decreases plasma levels but does not affect bio availability. Less than 10% of the dmg is bound to plasma proteins. Therapeutic plasma concentrations are 3—9 jig/mL. Toxic plasma levels are >10 fig/mL. Peak plasma concentrations are achieved in 0.5—2 h. About 30—40% of tocainide is metabolized in the fiver by deamination and glucuronidation to inactive metabolites. The metabolism is stereoselective and the steady-state plasma concentration of the (3)-(—) enantiomer is about four times that of the (R)-(+) enantiomer. About 50% of the tocainide dose is efirninated by the kidneys unchanged, and the rest is efirninated as metabolites. The elimination half-life of tocainide is about 15 h, and is prolonged in patients with renal disease (1,2,23). 

Ventricular fibrillation should be terminated by electrical defibrillation. Alternatively, lidocaine can be injected intravenously. In cases with lower frequency, ventricular tachyarrhythmia class I diugs such as aj marine, flecainide or propafenone are more effective as a result of the use-dependence of lidocaine. For prophylaxis treatment, amiodarone or sotalol may be helpful or the implantation of a cardioverter-defibrillator system. Acute amiodarone (i.v. in higher doses) can also terminate ventricular tachyarrhythmias. This action, however, seems to be mediated by its INa-blocking side effects and not (or less) by its class III like effects. 

Atropine, epinephrine, and lidocaine can be administered through the tracheal tube before venous access is achieved at 2-2.5 times the recommended intravenous dose diluted with 10 mL of normal saline or sterile water. Stop CPR, administer beyond the tip of the endotracheal tube, follow with five quick insufflations to aerosolize the drug, and then resume CPR. 

Lidocaine Dizziness, confusion, seizures (if dose too high)... 

Alternatively, a continuous magnesium infusion may be initiated after the first bolus, at a rate of 0.5 to 1 g/hour. Alternative treatments include transvenous insertion of a temporary pacemaker for overdrive pacing, which shortens the QT interval and may terminate torsades de pointes intravenous isoproterenol 2 to 10 mcg/minute, to increase the heart rate and shorten the QT interval intravenous lidocaine, which may shorten the duration of ventricular repolarization or intravenous phenytoin, which may also shorten the duration of ventricular repolarization, administered at a dose of 10 to 15 mg/kg infused at a rate of 25 to 50 mg/minute. 

Lidocaine can be considered an alternative to amiodarone in patients with VF/ PVT, The initial dose is 1-1,5 mg/kg IV. Additional doses of 0.5-0.75 mg/kgcan be administered at 5-to 10-minute intervals to a maximum dose of 3 mg/kg if VF/PVT persists. 

If neither IV nor IO access can be established, atropine, lidocaine, epinephrine, naloxone, and vasopressin may be administered endotracheally. The endotracheal dose should generally be two to two and one-half times larger than the IV/IO dose. 

Lidocaine is not recommended unless other agents have failed. Table 56-3 shows the recommended dosing guidelines. It has a rapid onset of action. Fasciculations, visual disturbances, and tinnitus may occur at serum concentrations between 6 and 8 mg/L. Seizures and obtundation may develop when serum concentrations exceed 8 mg/L. 

A3. Ahmad, K., and Medzihradsky, F., Distribution of lidocaine in blood and tissues after single doses and steady infusion. Res. Commun. Chem. Pathol. Pharmacol. 2, 813-828 (1971). 

Unlabeled uses In pediatric patients with cardiac arrest, less than 10% develop ventricular fibrillation, and others develop ventricular tachycardia the hemodynamically compromised child may develop ventricular couplets or frequent premature ventricular beats. In these cases, administer 1 mg/kg lidocaine by the IV, intraosseous, or endotracheal route. A second 1 mg/kg dose may be given in 10 to 15 minutes. Start a lidocaine infusion if the second dose is required a third bolus may be needed in 10 to 15 minutes to maintain therapeutic levels. 

Absorption/Distribution - Lidocaine is ineffective orally it is most commonly administered IV with an immediate onset (within minutes) and brief duration (10 to 20 minutes) of action following a bolus dose. Continuous IV infusion of lidocaine (1 to 4 mg/min) is necessary to maintain antiarrhythmic effects. Following IM administration, therapeutic serum levels are achieved in 5 to 15 minutes and may persist for up to 2 hours. Higher and more rapid serum levels are achieved by injection into the deltoid muscle. Therapeutic serum levels are 1.5 to 6 mcg/mL serum levels greater than 6 to 10 mcg/mL are usually toxic. Lidocaine is approximately 50% protein bound (concentration-dependent). 

Survival Prophylactic single dose lidocaine administered in a monitored environment does not appear to affect mortality in the earliest phase of acute Ml, and may harm some patients who are later shown not to have suffered an acute Ml. Constant ECG monitoring Constant ECG monitoring is essential for proper administration. Have emergency resuscitative equipment and drugs immediately available. 

Lidocaine/Tetracaine Transdermal (Synera) [Topical Anesthetic] Uses Topical anesthetic adjunct to phlebotomy or dermal procedures Action Topical anesthetic Dose Adults Children >3 y. Phlebotomy Apply to intact skin 20-30 min prior to venipuncture Dermal procedures Apply to intact skin 30 min prior to procedure Caution [B, ] Contra Pts w/ allergy to... 

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