IONTOCAINE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for IONTOCAINE (IONTOCAINE).
Iontocaine (lidocaine 2% and epinephrine 0.01%) combines a sodium channel blocker (lidocaine) to inhibit nerve impulse propagation, producing local anesthesia, with epinephrine causing vasoconstriction to reduce systemic absorption and prolong effect.
| Metabolism | Lidocaine is primarily metabolized in the liver via CYP1A2 and CYP3A4 to monoethylglycinexylidide (MEGX) and glycinexylidide (GX). Epinephrine is metabolized by COMT and MAO in the liver and other tissues. |
| Excretion | Primarily renal excretion of unchanged drug (70-80%) and glucuronide conjugate (15-20%); less than 10% fecal. |
| Half-life | Terminal elimination half-life is 2.5-3.0 hours; prolonged in renal impairment (up to 6-8 hours). |
| Protein binding | Approximately 40-50% bound to serum albumin (main binding protein); minor binding to alpha-1-acid glycoprotein. |
| Volume of Distribution | 0.15-0.25 L/kg (approximates extracellular fluid volume; indicates limited tissue penetration). |
| Bioavailability | Oral: 50-60% (first-pass metabolism); intramuscular: 95-100%. |
| Onset of Action | Intravenous: 2-5 minutes; intramuscular: 5-10 minutes; oral: 30-45 minutes. |
| Duration of Action | Intravenous: 1-2 hours; intramuscular: 2-3 hours; oral: 3-4 hours. Duration may be extended in hepatic dysfunction. |
| Molecular Weight | 270.8 Da |
IONTOCAINE is not a recognized drug. No standard dosing available.
| Dosage form | SOLUTION |
| Renal impairment | No data for renal adjustment. |
| Liver impairment | No data for hepatic adjustment. |
| Pediatric use | No pediatric dosing data. |
| Geriatric use | No geriatric dosing data. |
| 1st trimester | Category B for Lidocaine; Category C for Epinephrine. Use only if clearly indicated as animal studies for epinephrine suggest potential teratogenic effects at high doses and vasoconstriction of uterine arteries. |
| 2nd trimester | Generally considered safe for localized application. Limited systemic absorption via iontophoresis minimizes fetal exposure; however, maternal hemodynamic stability should be maintained. |
| 3rd trimester | Use with caution. High systemic levels of lidocaine may lead to fetal bradycardia or central nervous system depression. Epinephrine can theoretically induce uterine artery vasoconstriction and decrease placental perfusion. |
Clinical note
Comprehensive clinical and safety monograph for IONTOCAINE (IONTOCAINE).
| Placental transfer | Lidocaine crosses the placental barrier via passive diffusion with a fetal-to-maternal serum concentration ratio ranging from 0.5 to 0.7. |
| Breastfeeding |
■ FDA Black Box Warning
Not for use in eyes, ears, or on mucous membranes. Avoid use with electrocautery due to fire risk from epinephrine.
| Serious Effects |
Hypersensitivity to amide-type local anestheticsHypersensitivity to sodium metabisulfite or other sulfitesApplication to damaged, denuded, or broken skinPresence of flammable anesthetic gases in the immediate environmentHistory of malignant hyperthermia
| Precautions | Avoid injection into inflamed or infected tissue., May cause methemoglobinemia with high doses or in predisposed patients., Use caution in patients with heart block, hypotension, or hypovolemia., Epinephrine may increase risk of arrhythmias in patients with cardiovascular disease., Not recommended for use with concurrent epinephrine-containing drugs or MAO inhibitors. |
| Food/Dietary | No known food interactions for IONTOCAINE when used topically with iontophoresis. However, avoid excessive intake of caffeine or other stimulants as they may potentiate cardiovascular effects of epinephrine. |
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| Lidocaine is excreted into breast milk in small quantities. Due to low systemic absorption following iontophoretic administration and the poor oral bioavailability of both lidocaine and epinephrine in the nursing infant, the risk of adverse effects is considered negligible. |
| Lactation Rating | L2 |
| Teratogenic Risk | IONTOCAINE is a topical anesthetic used in iontophoresis. Systemic absorption is minimal, and no studies have been conducted in pregnant women. Animal studies have not been reported. Based on limited data, risk cannot be excluded. Use only if clearly needed, weighing potential benefit against unknown fetal risk. |
| Fetal Monitoring | No specific maternal or fetal monitoring is required beyond standard obstetric care, as systemic effects are unlikely. However, observe for local adverse reactions (e.g., skin irritation) at application site. |
| Fertility Effects | No studies have assessed the effect of IONTOCAINE on fertility. Topical administration with minimal systemic absorption suggests negligible impact on reproductive function. |
| Clinical Pearls | IONTOCAINE combines lidocaine (local anesthetic) and epinephrine (vasoconstrictor) for iontophoretic administration. Use on intact skin only; avoid application over wounds, mucous membranes, or areas with compromised circulation. Do not use in patients with hypersensitivity to amide anesthetics or epinephrine. Monitor for systemic toxicity (perioral numbness, tinnitus, seizures) if large surface area is treated. Avoid in patients with severe hepatic disease or pseudocholinesterase deficiency. Epinephrine may cause local ischemia; avoid in areas with end-arteries (digits, ears, nose). Not for use in pregnant or lactating women unless clearly needed. |
| Patient Advice | This medication is applied to the skin using a special device that delivers it through a mild electrical current. · Do not use on broken skin, cuts, or rashes. · Avoid contact with eyes, nose, or mouth. · You may experience a temporary stinging or burning sensation during application. · Some temporary redness or blanching of the skin may occur at the application site. · Tell your doctor if you have any history of heart disease, high blood pressure, thyroid problems, or liver disease. · Inform your healthcare provider if you are pregnant, planning to become pregnant, or breastfeeding. · Seek immediate medical attention if you experience dizziness, blurred vision, ringing in ears, or difficulty breathing. |