XYLOCAINE 5% W/ GLUCOSE 7.5%
Clinical safety rating: caution
Comprehensive clinical and safety monograph for XYLOCAINE 5% W/ GLUCOSE 7.5% (XYLOCAINE 5% W/ GLUCOSE 7.5%).
Lidocaine is an amide-type local anesthetic that stabilizes the neuronal membrane by inhibiting sodium ion channels, thereby blocking the initiation and conduction of nerve impulses.
| Metabolism | Primarily metabolized in the liver via cytochrome P450 enzymes (CYP1A2 and CYP3A4) to active metabolites (e.g., monoethylglycinexylidide) and inactive metabolites. Less than 10% excreted unchanged in urine. |
| Excretion | Hepatic metabolism (90% N-dealkylation by CYP1A2/CYP3A4 to monoethylglycinexylidide and glycinexylidide); renal excretion of metabolites and parent drug (<10% unchanged); <1% biliary/fecal. |
| Half-life | 1.5-2 hours (terminal); prolonged in heart failure, hepatic disease, or elderly; neonates 3-6 hours due to immature hepatic function. |
| Protein binding | 65-75% bound to alpha-1-acid glycoprotein (AAG) and albumin. |
| Volume of Distribution | 0.5-1.0 L/kg (IV); smaller in neonates (0.3-0.5 L/kg) due to reduced adipose tissue and protein binding. |
| Bioavailability | Epidural/spinal: ~100%; oral: <35% (extensive first-pass metabolism); topical: negligible systemic absorption (unless broken skin or high-dose). |
| Onset of Action | Epidural: 5-15 min; spinal: immediate; peripheral nerve block: 4-6 min; infiltration: 2-5 min. |
| Duration of Action | Epidural/spinal: 60-90 min with epinephrine (plain: 30-60 min); peripheral block: 60-180 min depending on dose and site; infiltration: 30-60 min. |
| Molecular Weight | 234.34 |
Adult: 5-25 mL (250-1250 mg lidocaine) of 5% lidocaine with glucose 7.5% solution, administered by caudal or lumbar epidural injection, single dose. Max total dose: 1250 mg.
| Dosage form | INJECTABLE |
| Renal impairment | No specific dose adjustment for GFR; use with caution in severe renal impairment due to potential for metabolite accumulation. |
| Liver impairment | Child-Pugh A: no adjustment. Child-Pugh B: reduce dose by 50%. Child-Pugh C: avoid use or reduce dose by 75% with close monitoring. |
| Pediatric use | Weight-based dosing: 2-4 mg/kg of lidocaine, administered epidurally. Maximum single dose: 4 mg/kg. Not recommended for patients <12 kg body weight due to high concentration. |
| Geriatric use | Reduce dose by 20-50% due to decreased clearance and increased susceptibility to toxicity. Use lowest effective dose and monitor for neurologic and cardiovascular effects. |
| 1st trimester | Lidocaine crosses the placenta. Studies suggest no increased risk of major malformations with standard doses. Caution advised due to potential for fetal bradycardia. |
| 2nd trimester | Use only if clearly needed. Monitor for maternal hypotension and fetal distress. Epidural use is common with careful monitoring. |
| 3rd trimester | May cause fetal bradycardia and central nervous system depression. Use lowest effective dose. Avoid during late pregnancy if possible. |
Clinical note
Comprehensive clinical and safety monograph for XYLOCAINE 5% W/ GLUCOSE 7.5% (XYLOCAINE 5% W/ GLUCOSE 7.5%).
| Placental transfer | Lidocaine rapidly crosses the placenta via passive diffusion. Fetal levels are approximately 50-80% of maternal serum levels. |
| Breastfeeding | Lidocaine is excreted into breast milk in small amounts (milk:plasma ratio ~0.4). At therapeutic maternal doses, it is unlikely to cause adverse effects in nursing infants. However, caution is advised with high doses or prolonged use. |
■ FDA Black Box Warning
Risk of cardiac arrest and death when used for local anesthesia, especially in large doses or when injected intravascularly. Resuscitative equipment and trained personnel must be immediately available.
| Serious Effects |
Hypersensitivity to lidocaine or any componentSevere sinoatrial block, atrioventricular block (without pacemaker)Severe hypotension or cardiogenic shockSevere hepatic impairmentMyasthenia gravis
| Precautions | Avoid intravascular injection; aspirate before administration., Caution in patients with hepatic impairment, cardiac disease, or elderly., Risk of methemoglobinemia, especially with concomitant use of oxidizing agents., Monitor for neurological and cardiac toxicity during administration. |
| Food/Dietary | No specific food interactions with lidocaine spinal administration. However, avoid heavy meals before surgery as per standard fasting guidelines. No dietary restrictions post-procedure unless otherwise instructed by the surgeon. |
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| Lactation Rating | L2 (Probably Compatible) |
| Teratogenic Risk | Lidocaine crosses the placenta. Fetal bradycardia and neonatal central nervous system depression may occur with high maternal serum concentrations. No teratogenicity has been reported in humans; animal studies have not demonstrated fetal harm. Use during the first trimester is generally considered safe, but avoid paracervical block in the second and third trimesters due to risk of fetal acidosis and bradycardia. |
| Fetal Monitoring | Monitor maternal vital signs and fetal heart rate continuously during administration. Assess for signs of maternal central nervous system or cardiovascular toxicity (e.g., perioral numbness, tinnitus, seizures, hypotension). For epidural or spinal use, monitor fetal heart rate patterns (bradycardia may occur). |
| Fertility Effects | No adverse effects on fertility or reproductive performance have been observed in animal studies. There is no evidence that lidocaine impairs human fertility. |
| Clinical Pearls | Xylocaine 5% with glucose 7.5% is a hyperbaric lidocaine solution used for spinal anesthesia. The glucose increases the density of the solution, making it hyperbaric relative to cerebrospinal fluid, which allows for predictable spread by gravity. Administer with the patient in the lateral decubitus or sitting position to control the level of blockade. Onset is rapid (2-5 minutes) and duration is about 1-2 hours. Use only for low spinal (saddle) blocks or selective spinal anesthesia due to high concentration. Contraindicated in patients with hypovolemia, severe hypotension, or allergy to amide anesthetics. Monitor for signs of high spinal or total spinal anesthesia: bradycardia, hypotension, respiratory depression, and loss of consciousness. Resuscitation equipment must be immediately available. Do not use for epidural or intravenous regional anesthesia (Bier block). |
| Patient Advice | You will receive numbing medicine into your lower back to block sensation in your lower body for surgery. · You may feel a brief sting when the needle is inserted, followed by warmth and numbness in your legs and lower belly. · You will be unable to move your legs for 1 to 2 hours after the injection; do not attempt to get up until fully recovered. · Report any severe headache, chest pain, difficulty breathing, or changes in vision immediately. · Avoid driving or operating machinery for at least 24 hours after the procedure. |