Is Acetaminophen safe while breastfeeding?

Effects on the breastfed infant

A maculopapular rash on the upper trunk and face of a 2-month-old infant was probably caused by acetaminophen in breastmilk. The rash occurred after 2 days of therapy in the mother at a dose of 1 gram at bedtime. It subsided when the drug was discontinued and recurred 2 weeks later after another acetaminophen dose of 1 gram was taken by the mother.[ 5 ] Two papers report 14 women who breastfed after taking acetaminophen or its prodrug phenacetin with no adverse effects to their infants.[ 6 , 7 ] In a telephone follow-up study, mothers reported no side effects among 43 infants exposed to acetaminophen in breastmilk.[ 8 ] Two clinicians speculated that breastmilk exposure to acetaminophen during breastfeeding might be a risk factor for asthma and wheezing in the breastfed infants based on their personal observations.[ 9 ] However, these observations were uncontrolled and cannot be considered to be valid proof of an association.[ 10 ]

Effects on milk supply

A randomized study compared the use of ibuprofen 400 mg plus acetaminophen 1 gram every 6 hours for 24 hours to the same combination on demand after normal vaginal delivery. Women who received the analgesics on a fixed schedule were more likely to breastfeed their baby (98% vs 88%) than those receiving analgesics on demand, even though their average pain scores were not different.[ 11 ] A double-blind study compared acetaminophen 1000 mg to ibuprofen for pain control after vaginal delivery. No difference was seen between the two treatments in the percentage of mothers who initiated breastfeeding of their infants.[ 12 ]

Levels in milk

Maternal Levels. A single oral dose of 650 mg of acetaminophen was given to 12 nursing mothers who were 2 to 22 months postpartum. Peak milk levels of 10 to 15 mg/L occurred between 1 and 2 hours after the dose in all patients. Acetaminophen was undetectable ( 0.5 mg/L) in all mothers 12 hours after the dose. The authors calculated that an infant who ingested 90 mL of breastmilk every 3 hours would receive an average of 0.88 mg of acetaminophen or 0.14% (range 0.04 to 0.23%) of the mother's absolute dosage.[ 1 ] Using data from this study, an infant would receive a maximum of about 2% of the maternal weight-adjusted dosage. Three women took a single 500 mg dose of acetaminophen. Peak milk levels averaging 4.2 mg/L occurred within 2 hours after the dose.[ 2 ] Using data from this study, an infant would receive a maximum of about 3.6% of the maternal weight-adjusted dosage. Four women who were 2 to 8 months postpartum were given a single 1 gram dose of acetaminophen. Milk was completely emptied from one breast every 30 minutes for 3 to 3.5 hours, with a final sample from the opposite breast. Peak milk levels occurred between 1 and 2.5 hours after the dose. The acetaminophen level in the breast that was sampled only once had a lower level than the breast sampled at half-hour intervals. The authors estimated that a breastfed infant would receive an average of 1.1% and a maximum of 1.8% of the maternal weight-adjusted dosage. This dose is about 0.5% of the lowest recommended infant dose of acetaminophen.[ 3 ] Eighteen women taking acetaminophen 500 mg orally postpartum pain donated a total of 20 milk samples for analysis at random times at 5 to 6 days postpartum. Milk concentrations ranged from 2.5 mcg/L at 68 hours after a dose to 13.5 mg/L at 0.8 hours after a dose. Levels were generally lower with increased time after a dose.[ 4 ] Note that this paper does not state the number of doses taken prior to sampling, so steady-state was not guaranteed. The pharmacokinetic an

Alternatives LactMed lists

• Celecoxib
• Diclofenac
• Flurbiprofen
• Ibuprofen
• Indomethacin
• Naproxen
• Piroxicam