Lidocaine Test

Murray KT, Barbey JT, Kopelman HA, Siddoway LA, Echt DS, Woosley RL, Roden DM. Mexiletine and tocai-nide a comparison of antiarrhythmic efficacy, adverse effects, and predictive value of lidocaine testing. Clin Pharmacol Ther 1989 45(5) 553-61. 

True IgE-mediated anaphylactic reactions to LAs are extremely rare [11-13]. Only single cases have been reported in the literature with positive prick tests [ 14,15]. A case of a positive open patch test in a patient suffering from contact urticaria after topical application of lidocaine, pilocaine mixture (Emla cream) might represent a true IgE-mediated allergy [16]. The maj ority of immediate-type reactions are non-immune in nature. 

Bircher AJ, Messmer SL, Surber C, Rufli T Delayed-type hypersensitivity to subcutaneous lidocaine with tolerance to articaine confirmation by in vivo 22 and in vitro tests. Contact Dermatitis 1996 34 387-389. 23... 

MEGX is readily detected by HPLC and fluorescence polarization immunoassay techniques [14,21,25,40,41]. The test is simple, normally requiring a onetime blood sampling, and informative because it depends on the capacity of the hepatic enzymes to metabolize lidocaine. While the analysis of lidocaine metabolites is rapid, this method has not been adapted for continuous hepatic function monitoring, which may be possible with the radiolabeled analogues such as Tc-Sn-lidocaine iminodiacetic acid [42]. 

Drugs that may affect amiodarone include hydantoins, cholestyramine, fluoroquinolones, rifamycins, ritonavir, and cimetidine. Drugs that may be affected by amiodarone include anticoagulants, beta-blockers, calcium channel blockers, cyclosporine, dextromethorphan, digoxin, disopyramide, fentanyl, flecainide, hydantoins, lidocaine, methotrexate, procainamide, quinidine, and theophylline. Drug/Lab test interactions Amiodarone alters the results of thyroid function tests, causing an increase in serum T4 and serum reverse T3 levels and a decline in... 

Recently, specific binding to sodium channels was demonstrated for the state-dependent sodium channel blocker [3H]BPBTS [105]. BPBTS is a potent blocker of all sodium channel subtypes tested, including native TTX-resistant channels expressed in mouse sensory neurons. Binding of [3H]BPBTS is inhibited by the local anesthetics tetracaine and lidocaine at concentrations known to interact with channels in the open and/or inactivated state. 

In ophthalmology, both trans-scleral and transcomeal dmg delivery has been studied. Drags investigated include fluorescein, tobramycin, gentamicin, ticarcillin, cefazolin, dexamethasone and ketoconazole. Iontophoresis has been found to be both safe and effective in delivering the required doses locally, at the intended site of action. Excepting for lidocaine, which has been tested in human volunteers, all the other drags have been tested in rabbits. 

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). 

The tests allow judgement of the propensity of local anesthetics to induce symptoms of hepatic porphyria. The local anesthetics lidocaine, bupivacaine, etido-caine, mepivacaine, prilocaine and pyrocaine belong to this group, but procaine, butacaine, oxybuprocaine, proxymethacaine and tetracaine had no (or very slight) porphyrinogenic effect. 

The most used and validated probe drugs for C YP3 A phenotyping are midazolam and 14C-erythromycin (Watkins 1994). Alfentanyl, alprazolam, dapsone, dextromethorphan, lidocaine. nifedipine, omeprazole, quinine, verapamil have also been used but less frequently, and CYP3A specificity for some of them has been questioned. The endogenous 6(->-hydroxycortisol test (measurement of 6 3-hydroxycortisol cortisol ratio in urine) is only useful for detecting CYP3A induction, and may be influenced by renal CYP3 A activity. 

A 28-year-old nurse had generalized urticaria and collapsed while she was undergoing a gastroscopy for suspected Helicobacter pylori infection (24). Before the start of the procedure she was given lidocaine oral spray and intravenous diazepam 10 mg, and at the end intravenous flumazenil 1 mg. Skin prick tests and intradermal tests with diazepam 5 mg/ml produced a weal-and-flare reaction flumazenil 0.1 mg/ml and lidocaine 2% had no effect. 

Meyer-Wyss, B., Renner, E., Luo, H., Scholer, A. Assessment of lidocaine metabolite formation in comparison with other quantitative liver function tests. J. Hepatol. 1993 19 133-139... 

A 24-year-old man injured in a motorcycle accident was treated with viscous lidocaine and bacitracin zinc ointment for extensive abrasions on the extremities. Five minutes later, he developed symptoms of severe anaphylaxis and required adrenaline, antihistamines, intravenous fluids, and glucocorticoids. Two weeks later, only the prick test to bacitracin zinc ointment was positive. 

An 18-month-old infant died after swallowing an unknown amount of 2% viscous lidocaine. He rapidly became unwell at home, with convulsions, followed by an asystolic cardiorespiratory arrest. He was intubated and resuscitated by paramedics, but continued to have seizures. He was given anticonvulsants and cardiorespiratory resuscitation was unsuccessful. Toxicological tests identified high concentrations of lidocaine and its metabolites. 

A 79-year-old man developed a weeping dermatitis of the perianal skin, buttocks, and proximal thighs (32). In the previous 3 weeks, he had used Proctosedyl cream which contains cinchocaine (dibucaine). Patch tests were positive with Proctosedyl cream and 5% cinchocaine in petrolatum, while benzocaine, lidocaine, and clioquinol were negative. 

A 71-year-old Japanese man developed an itchy erythematous papular eruption after using an over-the-counter medicament for skin wounds (Makiron) for 1 month (34). Patch tests with the constituents showed positive reactions to dl-chlorphenamine maleate and cinchocaine hydrochloride (both 1% in petrolatum). Patch tests with lidocaine hydrochloride and mepivacaine hydrochloride showed no cross-sensitization. 

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