POLOCAINE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for POLOCAINE (POLOCAINE).
Local anesthetic that stabilizes the neuronal membrane by inhibiting the influx of sodium ions, thereby blocking nerve impulse propagation.
| Metabolism | Primarily metabolized by liver esterases and to a lesser extent by plasma pseudocholinesterase. |
| Excretion | Hepatic metabolism to 2,6-xylidine and 4-hydroxy-2,6-xylidine; <10% excreted unchanged in urine; approximately 70-80% of metabolites excreted renally, with <5% in feces. |
| Half-life | Terminal elimination half-life approximately 1.5-2.0 hours in adults; prolonged to 3-5 hours in hepatic impairment and neonates. |
| Protein binding | Approximately 64-78% bound to alpha-1-acid glycoprotein and albumin. |
| Volume of Distribution | Vd approximately 0.8-1.3 L/kg, indicating extensive extravascular distribution. |
| Bioavailability | Inhalation: 90-100% via nebulization; Topical: minimal systemic absorption; Intravenous: 100%. |
| Onset of Action | Inhalation: 2-4 minutes; Topical (mucous membranes): 2-5 minutes; Infiltration: 1-3 minutes; Nerve block: 4-8 minutes. |
| Duration of Action | Infiltration: 30-60 minutes; Nerve block: 60-90 minutes; Addition of epinephrine extends to 60-90 minutes for infiltration and 120-180 minutes for nerve blocks. |
| Molecular Weight | 269.34 |
100 mg orally every 12 hours
| Dosage form | INJECTABLE |
| Renal impairment | GFR 30-89 mL/min: no adjustment; GFR <30 mL/min: reduce dose to 50 mg every 12 hours; hemodialysis: 50 mg after dialysis |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: contraindicated |
| Pediatric use | 2 mg/kg orally every 12 hours; maximum 100 mg per dose |
| Geriatric use | Start at 50 mg every 12 hours; titrate based on renal function and tolerability |
| 1st trimester | Animal studies have shown teratogenic effects; limited human data. Use only if benefit outweighs risk. |
| 2nd trimester | May cause fetal bradycardia and acidosis; use only if clearly needed. |
| 3rd trimester | Risk of neonatal CNS depression and bradycardia; avoid near term. |
Clinical note
Comprehensive clinical and safety monograph for POLOCAINE (POLOCAINE).
| Placental transfer | Rapid placental transfer; fetal levels approximately 60-80% of maternal levels. |
| Breastfeeding | Excreted into breast milk in small amounts. Monitor infant for bradycardia and CNS depression. Use caution. |
| Lactation Rating |
■ FDA Black Box Warning
Not available.
| Serious Effects |
Hypersensitivity to amide local anestheticsSevere hypotensionComplete heart blockMyasthenia gravis
| Precautions | Risk of systemic toxicity (CNS and cardiovascular effects) due to inadvertent intravascular injection or overdose, Use with caution in patients with liver disease, May cause methemoglobinemia with high doses |
| Food/Dietary | No known food interactions with mepivacaine. Avoid alcohol or sedatives post-procedure as they may potentiate CNS depression. |
| Clinical Pearls |
Loading safety data…
| L3 |
| Teratogenic Risk | Polocaine (lidocaine) is classified as FDA Pregnancy Category B. Animal studies have not demonstrated teratogenic effects. In the first trimester, retrospective studies suggest no increased risk of major malformations. However, because of possible fetal bradycardia and central nervous system depression, use with caution in the second and third trimesters, especially near term. Paracervical block in the second trimester has been associated with fetal bradycardia and acidosis. Epidural or spinal administration may cause maternal hypotension, leading to reduced uteroplacental perfusion and fetal bradycardia. Use the minimum effective dose and monitor fetal heart rate. |
| Fetal Monitoring | During maternal administration, especially with epidural or spinal anesthesia, monitor maternal blood pressure and fetal heart rate continuously for signs of bradycardia or distress. Monitor for maternal signs of central nervous system toxicity (e.g., perioral numbness, tinnitus, metallic taste) and cardiovascular toxicity (e.g., hypotension, arrhythmias). After administration, observe for neonatal effects such as bradycardia, apnea, or hypotonia for at least 2 hours if large doses were given near delivery. |
| Fertility Effects | In animal studies, lidocaine did not impair fertility. There are no well-controlled human studies on fertility effects. At therapeutic doses, no significant impact on fertility is anticipated. However, high systemic levels may theoretically affect sperm motility or ovulation; clinically, such levels are rarely achieved except during overdose. |
| Polocaine (mepivacaine) is an amide-type local anesthetic with rapid onset (2-5 min) and intermediate duration (1-3 hours). Avoid use in patients with known amide anesthetic allergy. For epidural or caudal anesthesia, use preservative-free solutions. Reduce doses in elderly, debilitated, or hepatically impaired patients. Do not use for spinal anesthesia due to insufficient data. Monitor for CNS toxicity (seizures, drowsiness) and cardiovascular collapse with inadvertent intravascular injection. |
| Patient Advice | Inform your healthcare provider if you have liver disease, heart block, or a history of allergic reactions to anesthetics. · You may experience temporary numbness, tingling, or weakness in the area where Polocaine was injected. · Avoid driving or operating heavy machinery until the numbness has completely worn off. · Seek emergency care if you experience difficulty breathing, seizures, or severe headache after injection. · Report any prolonged numbness or muscle weakness to your doctor. |