Is Meperidine safe while breastfeeding?

Effects on the breastfed infant

In 2 controlled studies, repeated maternal post-cesarean section meperidine doses, including patient-controlled analgesia, caused diminished alertness and orientation in 3- to 4-day old, breastfed infants compared to equivalent doses of morphine.[ 7 , 10 ] Twenty breastfed (extent not stated) infants whose mothers had received patient-controlled epidural analgesia with meperidine for 48 to 72 hours postpartum. They were assessed with the Neurologic and Adaptive Capacity Score (NACS) at a median of 105 minutes after maternal meperidine cessation. The median NACS was 33.5 (range 24 to 38), which is similar to the average score of 35 in healthy infants with no drug effects.[ 9 ] Mothers who were delivering by nonemergency cesarean section using spinal analgesia were given either a single dose of 100 mg of meperidine intravenously after delivery (n = 52) or routine care (n = 49), which consisted of a diclofenac 100 mg suppository. The feeding behaviors of both groups were recorded within 48 hours after delivery. Readiness for feeding in the control group was greater than the meperidine group. The mean score of feeding behavior in the meperidine group was slightly, but significantly lower than the control group at 6 and 12 hours after delivery using the infant breastfeeding assessment tool (IBFAT). Several other measures of feeding behavior were not different between the groups.[ 11 ]

Effects on milk supply

Meperidine can increase serum prolactin.[ 12 ] However, the prolactin level in a mother with established lactation may not affect her ability to breastfeed. More importantly, meperidine is likely to interfere with infant nursing behavior when given during labor.[ 13 - 15 ] In one small study, women given promethazine with meperidine and secobarbital during labor, had the time to lactogenesis II prolonged by 14 hours. Women given meperidine or secobarbital without promethazine had lactogenesis II prolonged 7 hours compared to unmedicated women, but the difference was not statistically significant.[ 16 ] A randomized, multicenter trial compared the initiation rate and duration of breastfeeding in women who received high-dose epidural bupivacaine alone, or one of two low-dose combinations of bupivacaine plus fentanyl. A nonepidural matched control group, some of whom received systemic meperidine, was also compared. Women in the nonepidural group who received systemic meperidine had a lower breastfeeding initiation rate than in the epidural or unmedicated groups.[ 17 ] 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.[ 18 ] A randomized, nonblinded study compared the use of intramuscular meperidine 100 mg to intranasal (mean dose 486 mcg) or subcutaneous (mean dose 300 mcg) fentanyl for labor analgesia. More women in the meperidine group had difficulty establishing lactation (79%) than in the intranasal (39%) or subcutaneous (44%) fentanyl groups. Mothers who received meperidine reported more sedation, had longe

Levels in milk

Meperidine is metabolized to the inactive meperidinic acid and to the active metabolite normeperidine which has half the analgesic activity and at least twice the central nervous system excitatory activity of meperidine. The oral bioavailability of meperidine is about 50% in adults. Newborns have impaired meperidine metabolism and possibly a higher oral bioavailability than adults. Newborns may also experience more central nervous system depression from normeperidine than adults. The usual infant oral meperidine dose is 1 to 2 mg/kg while the usual intravenous dose is 1 mg/kg which results in neonatal plasma levels of about 200 to 500 mcg/L. Maternal Levels. In 9 mothers who were 3 to 7 days postpartum and had received a single 50 mg intramuscular dose of meperidine, the highest measured breastmilk level was 130 mcg/L and occurred 2 hours after the dose.[ 5 ] Using the peak meperidine milk level from this study, an exclusively breastfed infant would receive about 20 mcg/kg daily of meperidine. However, normeperidine was not measured in the study. Two breastfeeding mothers who were 8 to 72 hours postpartum and receiving about 500 mg daily of intravenous meperidine had their milk sampled 2 to 4 times over 48 to 72 hours. Relationships between dose timing and milk sampling were not stated. The reported range of measured meperidine milk levels were 165 to 311 mcg/L. Measured normeperidine milk levels were undetectable ( 1.6 mcg/L) during the first 12 hours postpartum in 1 patient and reached only 66 mcg/L during the same period in the other patient. In the 36 to 72 hour postpartum period, the reported range of measured normeperidine milk levels were 151 to 333 mcg/L.[ 6 ] Using the peak meperidine milk level from this study, an exclusively breastfed infant would receive about 50 mcg/kg daily of meperidine from a maternal intravenous meperidine regimen of 500 mg per day, equal to about 6% of the maternal weight-adjusted dosage. Using the peak normeperidine milk level fro

Alternatives LactMed lists

• Acetaminophen
• Butorphanol
• Fentanyl
• Hydromorphone
• Ibuprofen
• Morphine