Pharmacology lidocaine

Local anesthetics interact with peripheral nerve cell membranes and exert a pharmacological effect [34]. Potential oscillation was measured in the presence of 20 mM hydrochlorides of procaine, lidocaine, tetracaine, and dibucaine (structures shown in Fig. 16) [19]. Amplitude and the oscillatory and induction periods changed, the extent depending on the... 

In terms of pharmacological parameters, prilocaine is comparable to lidocaine however, because of a number of toxic manifestations, it is rarely used in medical practice. Citanest and xylonest are well-known synonyms for prilocaine. 

Pharmacology Therapeutic concentrations of lidocaine attenuate phase 4 diastolic depolarization, decrease automaticity and cause a decrease or no change in excitability and membrane responsiveness. Action potential duration and effective refractory period (ERP) of Purkinje fibers and ventricular muscle are decreased, while the ratio of ERP to action potential duration is increased. Lidocaine raises ventricular fibrillation threshold. AV nodal conduction time is unchanged or shortened. Lidocaine increases the electrical stimulation threshold of the ventricle during diastole. 

Mexiletine (Mexitil) is an antiarrhythmic agent with pharmacological and antiarrhythmic properties similar to those of lidocaine and tocainide. Like tocainide, mexiletine is available for oral administration. 

Concurrent administration of propafenone with digoxin, warfarin, propranolol, or metoprolol increases the serum concentrations of the latter four drugs. Cimetidine slightly increases the propafenone serum concentrations. Additive pharmacological effects can occur when lidocaine, procainamide, and quinidine are combined with propafenone. 

Of all the local anaesthetics available, levobupivacaine and ropivacaine have the most favourable pharmacological characteristics for use in obstetrics. They have the lowest potential for cardiotoxicity and, unlike lidocaine and prilocaine, there is little risk of cumulation when they are administered by epidural infusion at effective doses. Elimination of all amides is prolonged in the neonate, exceeding 20 h in the case of bupivacaine. 

PURPOSE AND RATIONALE Surface anesthesia is used to anesthetize the cornea and conjunctiva of the eye and the mucous membranes in the mouth. The classical pharmacological test is the blockade of the rabbit corneal reflex as described by Regnier (1923) that has become a standard test method for evaluating local anesthetics (FuBganger and Schaumann 1931 Ther 1953a Quevauviller 1971 Muschaweck et al. 1986). These pharmacological methods are only partially suitable to determine the irritancy potential of local anesthetic on mucus membranes. Luduena et al. (1960) compared the mucus membrane irritancy of mepivacaine and lidocaine by the eye irritation method according to Hoppe (1950) and Draize et al. (1944). 

Lidocaine is broken down primarily in the liver by oxidative N-dealkylation. This step can occur only to a restricted extent in pri-locaine and carticaine because both carry a substituent on the C-atom adjacent to the nitrogen group. Carticaine possesses a car-Luellmann, Color Atlas of Pharmacology All rights reserved. Usage subject to terms... 

For refractory cases consider additional pharmacological agents aminodarone. lidocaine, procainamide or sotalol ... 

The use of in vitro fertilization has raised the question of whether the use of local anesthetics during oocjde removal is innocuous or not. Pharmacological concentrations of anesthetic agents are found in folhcular fluid (44). No clinical effects have been noted, but knowledge of the behavioral effects of lidocaine on offspring in rats must cause some concern (SEDA-15,117). 

Mofenson HC, Caraccio TR, Miller H, Greensher J. Lidocaine toxicity from topical mucosal application. With a review of the clinical pharmacology of lidocaine. CUn Pediatr (Phila) 1983 22(3) 190-2. 

What is the primary pharmacology and side effects of lidocaine ... 

Baggot J D 1992 Bioavailability and bioequivalence of veterinary drug dosage forms, with particular reference to horses an overview. Journal of Veterinary Pharmacology and Therapeutics 15 160-173 Dirikolu L, Lehner A F, Karpiesiuk W et al 2000 Identification of lidocaine and its metabolites in post-administration equine urine by ELISA and MS/MS. Journal of Veterinary Pharmacology and Therapeutics 23 215-222 Evans W E 1992 General principles of applied... 

Keenaghan, J.B. Boyes, R.N. (1972) The tissue distribution, metabolism and excretion of lidocaine in rats, guinea pigs, dogs and man. Journal of Pharmacology and Experimental Therapeutics, 180, 454-463. 

Branch, R.A., Shand, D.G., Wilkinson, G.R. Nies, A.S. (1973) The reduction of lidocaine clearance by di-propranolol an example of hemodynamic drug interaction. Journal of Pharmacology and Experimental Therapeutics, 184, 515-519. 

Engelking, L.R., Blyden, G.T., Lofstedt, J. Greenblatt, D.J. (1987) Pharmacokinetics of antipyrine, acetaminophen and lidocaine in fed and fasted horses. Journal of Veterinary Pharmacology and Therapeutics, 10, 73-82. 

Lidocaine, proprietary name Xyhcaine, is the drug of choice for the initial therapy of PVCs and the prevention of ventricular arrhythmias. Lidocaine is contraindicated when bradycardias and severe atrioventricular node block appear after myocardial infarction. Lidocaine shortens the action potential refractory period in these fibers and does so at concentrations less than those required to exert pharmacological effects at other sites, such as the ventricular myocardium. 

The total plasma concentration of lidocaine is a result of clearance of the drug and is modulated by hepatic function. There is little impact on clearance in renal disease. In situations of decreased organ perfusion, clearance is reduced and increased blood concentrations of lidocaine should be expected reduced dosing is appropriate in these circumstances. The principal binding protein of Hdocaine, AAG, has been demonstrated to accumulate after myocardial infarction. The result of accumulation of this protein is reduction of free lidocaine, which reduces the pharmacological effect of the drug. Lidocaine is usually analyzed by immunoassay, and MEGX and GX by HPLC. 

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