Lidocaine iontophoresis

Zempsky, W.T., et al. 2004. Evaluation of a low-dose lidocaine iontophoresis system for topical anesthesia in adults and children A randomized, controlled trial. Clin Ther 26 1110. 

Administration of local anesthetics via iontophoresis can also be used to produce topical anesthesia prior to certain dermatologic procedures. For example, lidocaine iontophoresis can adequately anesthetize a small patch of skin for performing a minor surgical procedure (placement of an intravenous catheter, laser treatment of port-wine stains, and so forth).18,50,66 Ion-tophoretic application of local anesthetics offers... 

Rose JB, Galinkin JL, Jantzen EC, Chiavacci RM. A study of lidocaine iontophoresis for pediatric venipuncture. Anesth Analg. 2002 94 867-871. 

Monteiro-Riviere, N. A. Altered epidermal morphology secondary to lidocaine iontophoresis in vivo and in vitro studies in porcine skin. Fundam. Appl. Toxicol. I5 m, 1990. 

Zempsky, WT, Anand KS, Sulhvan KM, et al. Lidocaine iontophoresis for topical anesthesia before intravenous line placement in children. J Pediatr 1998 132 1061-1063. 

Riviere, J.E., Sage, B., and Williams, RL, Effects of vasoactive drugs on transdermal lidocaine iontophoresis, J. Pharm. Sci., 1991, 80, 615-620. 

Application of this model to published data on the iontophoresis of lidocaine [32,78] in the binary system lidocaine-sodium shows a good agreement between experiment and prediction (Figure 14.5). On the other hand, discrepancies have been found for ropinirole [66] in this case, parallel increments in the concentrations of the drug and sodium were undertaken to maintain their molar fractions constant. While Equation 14.8 predicts that the drug flux should remain constant under these circumstances, ropinirole flux actually decreased as the sodium concentration increased. Clearly, further research is required to optimize the form of this model. 

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. 

Iontophoresis of mepivacaine and lidocaine with epinephrine have been reported in human cadaver bladders and in clinical trials by Lugnani et al. [41], The study reported that the active electrode must be sited close to the geometric center of the bladder cavity in order to anesthesize the entire bladder. Siting the electrode close to the wall resulted in anesthesia of only that section of the bladder. 

Iontophoresis has been used to deliver local anesthetics in the field of dentistry. Gangarosa [45] reported the iontophoresis of a 2% solution of lidocaine, with epinephrine (1 100,000) for the local anesthesia for extraction of retained deciduous teeth. Iontophoresis has also been used to desensitize teeth [46]. 

Iontophoresis in the ear to relieve pain was reported by Albrecht in 1911 [47]. He used cocaine in high concentrations (20%-40%), copper electrodes, and uncontrolled high current (1.5-2 mA) on perforated tympanic membranes. Despite excellent anesthesia, many of his patients were vertiginous during and after treatment, with some patients suffering permanent loss of hearing. However, relatively recent studies have demonstrated that the use of lidocaine [48], A-acetylcysteine [49], or dexamethasone and fosfomycin [50] in iontophoresis to the ear has no adverse effects in either animal or clinical trials. Echols et al. [51] confirmed that lidocaine could be iontophoresed in the middle ear for at least 30 minutes at 1 mA without any adverse effects. 

Singh and Roberts [63] have shown that iontophoretic delivery through intact epidermis yields deeper tissue concentrations, identical to that after dermal delivery. Figure 4 shows similar tissue concentrations for lidocaine and salicylate after iontophoretic delivery through intact skin and passive application of these solutes to the dermis. It is therefore concluded that iontophoresis... 

Figure 4 Comparison of dermal diffusion and epidermal iontophoresis in tissues of lidocaine and salicylic acid after 2 hours application.

Sato, H., Takahashi, H., and Honjo, I. Transtympanic iontophoresis of dexameth-asone and fosfomycin. Arch. Otolaryngol. Head Neck Surg. 114 531, 1988. Echols, D. F., Norris, C. H., and Tabb, H. G. Anesthesia of the ear by iontophoresis of lidocaine. Arch. Otolaryngol. 707 418, 1975. 

Riviere, J. E., Monteiro-Riviere, N. A., and Inman. A. Determination of lidocaine concentrations in skin after transdermal iontophoresis Effects of vasoactive drugs. Pharm. Res. 9 211, 1992. 

Arvidsson, S. B., Ekroth, R. H., Hansby, A. M. C., Lindholm, A. H., and William-Olsson, G. Painless venipuncture. A clinical trial of iontophoresis of lidocaine for venipuncture in blood donors. Acta Anaesthesiol. Scand. 25 209, 1991. 

Iontophoresis is a means of penetrating the skin with a topical anesthetic using mild electric current. Lidocaine-soaked sponges are applied to the skin, and electrodes are placed on top of the anesthetic pads. Anesthesia can be obtained within 15 to 30 minutes, achieving an anesthetic depth of 1 to 2 cm.This route is infrequently used due to the expense and inconvenience of the apparatus. 

The most common therapeutic applications of iontophoresis are topical administration of lidocaine as a local anesthetic and dexamethasone for treatment of local inflammation (lomed, Inc., Salt Lake City, Utah and Empi Corp., Minneapolis, Monnesota). In addition to these therapeutic uses, iontophoretic... 

Lidocaine (L) and epinephrine Male and female (5-15) Back, chest, dorsum of hand, antecubital fossa (randomly chosen) IDDS iontophoresis L concentration in plasma and skin reaction Plasma L in all subjects was <10ng/mL irrespective of sites. No erythema or edema from L was found. Erythema associated with the anode appeared to be more prominent at the chest or back. ... 

S. W. Qu, S. Percutaneous lidocaine administration via new iontophoresis system in children tolerability and absence of systemic bioavailability. Pediatrics 2003, 112, 578-582. 

Iontophoresis Small current applied to lidocaine-soaked sponges on intact skin Onset 10 minutes Duration 10-20 minutes. Good for small procedures, depth of anesthesia greater than EMLA Stinging sensation may bum skin if high current... 

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