POLOCAINE W/ LEVONORDEFRIN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for POLOCAINE W/ LEVONORDEFRIN (POLOCAINE W/ LEVONORDEFRIN).
Polocaine (mepivacaine) is an amide local anesthetic that blocks sodium ion channels in nerve cell membranes, inhibiting the initiation and conduction of nerve impulses. Levonordefrin is a vasoconstrictor that acts as an alpha-adrenergic agonist, causing local vasoconstriction to reduce systemic absorption of mepivacaine and prolong duration of action.
| Metabolism | Mepivacaine is primarily metabolized in the liver via N-demethylation to pipecoloxylidide, an active metabolite, and further metabolized by hydroxylation. Major CYP450 enzymes involved: CYP1A2, CYP3A4. Levonordefrin is metabolized by catechol-O-methyltransferase (COMT) and monoamine oxidase (MAO). |
| Excretion | Renal excretion of unchanged drug and metabolites accounts for >90% of elimination; <2% excreted unchanged in urine; major metabolites are glucuronide and sulfate conjugates excreted renally; biliary excretion is minor. |
| Half-life | Terminal elimination half-life of prilocaine is approximately 1.5 hours (range 1-2 hours); clinically, this correlates with duration of anesthesia for infiltration and nerve block procedures. |
| Protein binding | Prilocaine is approximately 55% bound to plasma proteins, primarily albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | Volume of distribution of prilocaine is 1.0-1.5 L/kg; indicates moderate tissue distribution with extensive uptake into highly perfused organs. |
| Bioavailability | Bioavailability is 100% after intravenous administration; for infiltration or nerve block, systemic absorption is route-dependent but near complete with rapid absorption. |
| Onset of Action | Onset of action for infiltration anesthesia is 2-5 minutes; for nerve block, 5-15 minutes; maximal effect achieved within 5-15 minutes. |
| Duration of Action | Duration of anesthesia is approximately 30-90 minutes for infiltration and 1-3 hours for nerve block; addition of levonordefrin prolongs duration by 50-100% compared to plain prilocaine. |
| Molecular Weight | Lidocaine: 234.34 Da; Epinephrine: 183.20 Da |
Dental local anesthesia: 1:100,000 epinephrine equivalent. For Polocaine (mepivacaine) 2% with levonordefrin 1:20,000, typical adult dose: 1-3 mL infiltrations or 2-4 mL nerve blocks; maximum 6.8 mg/kg (mepivacaine) or about 5.8 mL of 2% solution for a 70 kg adult. Maximum per session: 20 mL of 2% mepivacaine.
| Dosage form | INJECTABLE |
| Renal impairment | No specific dose adjustment guidelines for mepivacaine in renal impairment. Use with caution due to potential accumulation of metabolites; monitor for toxicity. eGFR <30: consider reduced doses. |
| Liver impairment | Child-Pugh A: No adjustment. Child-Pugh B: Reduce dose by 50%. Child-Pugh C: Avoid use; consider alternative. |
| Pediatric use | Maximum mepivacaine dose: 5-6 mg/kg (2% solution = 5 mg/mL). Typical: 0.5-1.0 mL per site; total dose not to exceed calculated maximum based on weight. For children <20 kg: use 0.5 mg/kg per injection, maximum 2 mL. |
| Geriatric use | Elderly patients: reduce dose due to decreased metabolic capacity and potential comorbidities. Administer smallest effective volume; monitor for cardiovascular effects (levonordefrin is a vasoconstrictor). |
| 1st trimester | Generally considered safe; use only if clearly needed. No well-controlled studies in pregnant women, but animal studies have not shown fetal risk. |
| 2nd trimester | Generally considered safe; use only if clearly needed. Same considerations as first trimester. |
| 3rd trimester | Generally considered safe; use only if clearly needed. Avoid high doses near term due to potential for uterine contractions and fetal bradycardia. |
Clinical note
Comprehensive clinical and safety monograph for POLOCAINE W/ LEVONORDEFRIN (POLOCAINE W/ LEVONORDEFRIN).
| Placental transfer | Lidocaine and epinephrine cross the placenta. Lidocaine has a fetal/maternal ratio of approximately 0.4-0.7. Epinephrine is extensively metabolized and does not accumulate significantly. |
| Breastfeeding | Excreted into breast milk in small amounts. The American Academy of Pediatrics considers compatible with breastfeeding. Monitor infant for irritability or sleep disturbances. |
■ FDA Black Box Warning
Not available. There is no FDA boxed warning for this product.
| Serious Effects |
Hypersensitivity to lidocaine, epinephrine, or any componentSevere hypotensionCocaine-induced vasoconstrictionConcurrent use of MAO inhibitors or tricyclic antidepressants (within 14 days)Use in areas with end-arteries (e.g., digits, nose, ears) due to risk of ischemia
| Precautions | Risk of systemic toxicity if accidentally injected intravenously, Use with caution in patients with hepatic impairment (reduced metabolism), Avoid in patients with severe hypertension, hyperthyroidism, or cardiovascular disease due to levonordefrin, May cause methemoglobinemia with high doses or in susceptible patients, Avoid concurrent use with MAO inhibitors or tricyclic antidepressants (hypertensive crisis risk) |
| Food/Dietary | Avoid consuming alcohol for at least 24 hours after administration as it may increase dizziness and risk of bleeding. No specific food restrictions, but avoid hot foods and beverages until anesthesia resolves to prevent oral burns. |
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| Lactation Rating | L2 (Safer) |
| Teratogenic Risk | Pregnancy Category C. Lidocaine crosses the placenta with fetal serum levels approximately 50% of maternal levels. In first trimester, risks are low but no well-controlled studies. Second and third trimesters: potential for fetal bradycardia due to local anesthetic systemic toxicity; dose-related. Levonordefrin (vasoconstrictor) may reduce uterine blood flow; contraindicated in severe hypotension or preeclampsia. |
| Fetal Monitoring | Monitor maternal vital signs (BP, HR, ECG) and fetal heart rate if feasible. Observe for signs of local anesthetic systemic toxicity (LAST): perioral numbness, metal taste, tinnitus, seizures, cardiac arrhythmias. Avoid rapid injection or high doses. |
| Fertility Effects | No specific human data on fertility impact. In animal studies, lidocaine and levonordefrin at clinically relevant doses did not impair fertility. Vasoconstriction from levonordefrin theoretically could affect uterine receptivity, but no evidence. |
| Clinical Pearls | Polocaine with levonordefrin is a dental local anesthetic containing mepivacaine 2% with levonordefrin 1:20,000. Levonordefrin is a vasoconstrictor that prolongs anesthetic action and reduces systemic absorption. Contraindicated in patients with severe cardiovascular disease, hyperthyroidism, or sulfite allergy (levonordefrin contains sodium bisulfite). Use with caution in patients on MAOIs or tricyclic antidepressants due to risk of hypertensive crisis. Maximum dose: mepivacaine 5.4 mg/lb (30 mg for pediatric or 400 mg total), levonordefrin 0.2 mg per appointment. Avoid intravascular injection to minimize systemic toxicity. |
| Patient Advice | Temporary numbness of lips, tongue, and face is expected; avoid chewing or hot foods until numbness resolves. · Do not bite or injure numb tissue, especially for children. · If you experience rapid heart rate, dizziness, or chest pain, contact your dentist or seek emergency care. · Inform your dentist of all medications, especially MAOIs, antidepressants, or thyroid medications. · Report any allergic reactions such as rash, swelling, or difficulty breathing immediately. |