Lidocaine

The Basics

What is Lidocaine?

Used on different parts of the body to cause numbness and to relieve pain and itching caused by conditions such as sunburn or other minor burns, insect bites or stings, poison ivy, poison oak, poison sumac, minor cuts, or scratches.

Brand names for Lidocaine

Xylocaine

How Lidocaine is classified

Antiarrhythmics, Local Anesthetics

Lidocaine During Pregnancy

Lidocaine pregnancy category

Category BNote that the FDA has deprecated the use of pregnancy categories, so for some medications, this information isn’t available. We still think it’s useful to list historical info, however, given what a common proxy this has been in the past.

What we know about taking Lidocaine while pregnant

Reproduction studies for lidocaine have been performed in both rats and rabbits. There was no evidence of harm to the fetus at subcutaneous doses of up to 50 mg/kg lidocaine (300 mg/m2 on a body surface area basis) in the rat model. In the rabbit model, there was no evidence of harm to the fetus at a dose of 5 mg/kg, s.c. (60 mg/m2 on a body surface area basis). Treatment of rabbits with 25 mg/ kg (300 mg/m2) produced evidence of maternal toxicity and evidence of delayed fetal development, including a non-significant decrease in fetal weight (7%) and an increase in minor skeletal anomalies (skull and sternebral defect, reduced ossification of the phalanges). The effect of lidocaine on post-natal development was examined in rats by treating pregnant female rats daily subcutaneously at doses of 2, 10, and 50 mg/kg (12, 60, and 300 mg/m2) from day 15 of pregnancy and up to 20 days postpartum. No signs of adverse effects were seen either in dams or in the pups up to and including the dose of 10 mg/kg (60 mg/m2); however, the number of surviving pups was reduced at 50 mg/kg (300 mg/m2), both at birth and the duration of lactation period, the effect most likely being secondary to maternal toxicity. No other effects on litter size, litter weight, abnormalities in the pups and physical developments of the pups were seen in this study. A second study examined the effects of lidocaine on post-natal development in the rat that included assessment of the pups from weaning to sexual maturity. Rats were treated for 8 months with 10 or 30 mg/kg, s.c. lidocaine (60 mg/m2 and 180 mg/m2 on a body surface area basis, respectively). This time period encompassed 3 mating periods. There was no evidence of altered post-natal development in any offspring; however, both doses of lidocaine significantly reduced the average number of pups per litter surviving until weaning of offspring from the first 2 mating periods. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

Taking Lidocaine While Breastfeeding

What are recommendations for lactation if you're taking Lidocaine?

Lidocaine concentrations in milk during continuous IV infusion, epidural administration and in high doses as a local anesthetic are low and the lidocaine is poorly absorbed by the infant. Lidocaine is not expected to cause any adverse effects in breastfed infants. No special precautions are required.[1][2][3] Lidocaine during labor and delivery with other anesthetics and analgesics has been reported by some to interfere with breastfeeding. However, this assessment is controversial and complex because of the many different combinations of drugs, dosages and patient populations studied as well as the variety of techniques used and deficient design of many of the studies. Overall it appears that with good breastfeeding support epidural lidocaine with or without fentanyl or one of its derivatives has little or no adverse effect on breastfeeding success.[4][5][6][7][8] Labor pain medication may delay the onset of lactation.

Maternal / infant drug levels

Lidocaine concentrations in milk during continuous IV infusion, epidural administration and in high doses as a local anesthetic are low and the lidocaine is poorly absorbed by the infant. Lidocaine is not expected to cause any adverse effects in breastfed infants. No special precautions are required.[1][2][3] Lidocaine during labor and delivery with other anesthetics and analgesics has been reported by some to interfere with breastfeeding. However, this assessment is controversial and complex because of the many different combinations of drugs, dosages and patient populations studied as well as the variety of techniques used and deficient design of many of the studies. Overall it appears that with good breastfeeding support epidural lidocaine with or without fentanyl or one of its derivatives has little or no adverse effect on breastfeeding success.[4][5][6][7][8] Labor pain medication may delay the onset of lactation.

Possible effects of Lidocaine on milk supply

A randomized study compared three groups of women undergoing elective cesarean section who received subcutaneous infusion of 20 mL of lidocaine 1% plus epinephrine 1:100:000 at the incision site. One group received the lidocaine before incision, one group received the lidocaine after the incision, and the third received 10 mL before the incision and 10 mL after. Women in the pre-and post-incision administration group initiated breastfeeding earlier than those in the pre-incision administration (3.4 vs 4.1 hours). There was no difference between the post-incision administration group and the other groups in time to breastfeeding initiation.[12]

A national survey of women and their infants from late pregnancy through 12 months postpartum compared the time of lactogenesis II in mothers who did and did not receive pain medication during labor. Categories of medication were spinal or epidural only, spinal or epidural plus another medication, and other pain medication only. Women who received medications from any of the categories had about twice the risk of having delayed lactogenesis II (>72 hours) compared to women who received no labor pain medication.[13]

An Egyptian study compared lidocaine 2% (n = 75) to lidocaine 2% plus epinephrine 1:200,000 (n = 70) as a wound infiltration following cesarean section. Patients who received epinephrine in combination with lidocaine began breastfeeding at 89 minutes following surgery compared to 132 minutes for those receiving lidocaine alone. The difference was statistically significant.[14]

Possible alternatives to Lidocaine

Bupivacaine, Ropivacaine.