Adverse Drug Reactions in Breastfed Infants: Less Than Imagined

Abstract

Medication use during breastfeeding shortens the duration of breastfeeding often because of overly cautious information given by healthcare providers. No comprehensive review of the literature on infant adverse reactions from drugs in breastmilk has been published. All published studies and case reports on adverse events in infants caused by medications (excluding drugs of abuse) in breastmilk were identified and analyzed. Of 100 case reports evaluated, none were considered to be "definite" using a standard ranking scale; 47% were "probable" and 53% were "possible." Drugs with central nervous system activity accounted for half of all reports. All 3 reported fatalities involved central nervous system depressants, but each had extenuating circumstances. At least 63% of reported cases were in neonates and 78% were in infants 2 months or younger; only 4% of adverse reactions occurred in infants older than 6 months of age. Published studies expand on and generally reinforce the analysis of case reports. By taking a few simple precautions in drug selection and considering the infant's age, breastfeeding rarely needs to be discouraged or discontinued when a mother needs drug therapy.

A Review of Adverse Reactions in Infants From Medications in Breastmilk

“…71 In our previous article, 51% of cases involved CNS depressants, and in this study, they account for 69%. 1 Overall, of the 153 cases from our 2 reviews, 88 (58%) cases involved drugs with CNS activity. All deaths reported in this article and in our previous article involved one or more CNS depressants.…”

“…1 In this article, we used the same methodology to collect and assess case reports since 2002. We also reviewed studies designed to determine the frequency of adverse effects from specific drugs or drug classes.…”

The Transfer of Drugs and Therapeutics Into Human Breast Milk: An Update on Selected Topics

“…In addition, unexplained apnea, bradycardia, cyanosis, and sedation have been reported in nursing infants of mothers receiving codeine. 2,66 Hydrocodone is also metabolized via the CYP2D6 pathway. On the basis of pharmacokinetic data, infants exposed to hydrocodone through human milk may receive up to 9% of the relative maternal dose.…”

“…The age of the infant is also an important factor in the decision-making process, because adverse events associated with drug exposure via lactation occur most often in neonates younger than 2 months and rarely in infants older than 6 months. 2 In the near future, pharmacogenetics may also provide important guidance for individualized decisions.…”

Hydrocodone Excretion into Breast Milk: The First Two Reported Cases

“…An extensive review of the published literature on adverse reactions from maternal medications in breastfed infants found that 78% of published cases occurred in infants under 2 months of age and only 4% of published cases were in infants over 6 months of age. 9 Infants reported to have adverse reactions involving hydrocodone were 18 days and 5 weeks of age. 2,3 Similarly, the death from codeine and its metabolites in breast milk occurred in a 13-day-old infant.…”