Ampicillin and Breastfeeding

Summary of use during lactation

Substantial information indicates that ampicillin produces low levels in milk that are not expected to cause adverse effects in breastfed infants. Occasionally disruption of the infant's gastrointestinal flora, resulting in diarrhea or thrush have been reported with penicillins, but these effects have not been adequately evaluated. Ampicillin is acceptable in nursing mothers.

Drug levels in milk and infant serum

Maternal Levels. After an ampicillin oral dose of 500 mg every 6 hours for 3 days, milk levels fluctuated little and ranged from 0.575 to 1 mg/L (mean 0.8 mg/L) at various times in one mother and 0.014 mg/L to 0.0675 mg/L (average 0.03 mg/L) in another.[1] In 10 mothers given ampicillin 1.5 or 2 grams daily by mouth for 3 doses had milk levels ranging from 0.03 to 0.2 mg/L. Another mother receiving 3 grams daily by mouth had milk levels of 0.08 to 0.3 mg/L. In 3 mothers who received 2 grams daily intramuscularly, milk levels ranged from 0.3 to 0.9 mg/L and in 3 mothers who received 4 grams daily intramuscularly had milk levels of 0.4 to 0.9 mg/L. In all cases, peak milk levels occurred 3 hours after the dose. The breastfed infant was estimated to receive from 0.08 to 0.2 mg daily of ampicillin with these doses.[2] A study in postpartum women with endometritis who received ampicillin 1 or 2 grams infused intravenously over 20 minutes found the average milk levels of ampicillin to be 1.7 mg/L with the highest level observed 3 mg/L.[3] In 15 women receiving ampicillin 500 mg 4 times daily by intramuscular injection, average milk ampicillin levels were as follows: 0.11 mg/L at 30 minutes after the injection; 0.21 mg/L at 1 hour, 0.17 at 2 hours, 0.27 mg/L at 4 hours and 0.26 mg/L at 6 hours after the injection.[4] In 13 women with mastitis who received 1 gram of ampicillin orally 4 times daily, the average milk concentrations ranged from 0.6 to 1.05 mg/L.[5] In 15 women given a single 2 grams dose of ampicillin intravenously, milk levels averaged 1.1 mg/L 2 hours after the dose.[6] Infant Levels. Thirteen women with mastitis received 1 gram of ampicillin orally 4 times daily. Ampicillin was detectable in the urine in only 2 of 8 of the breastfed infants in whom it was measured.[5]

Effects in breastfed infants

An uncontrolled observation of the breastfed infants of mothers taking ampicillin noted a seeming increase in cases of diarrhea and candidiasis that was attributed to ampicillin in breastmilk.[7] In a prospective follow-up study, 5 nursing mothers reported taking ampicillin (dosage unspecified). One mother reported diarrhea in her infant. No rashes or candidiasis were reported among the exposed infants.[8] A small, controlled, prospective study had mothers monitor their infants for signs of adverse effects (furring of the tongue, feeding difficulties, changes in stool frequency and consistency, diaper rash, and skin rash). Weight change and the development of jaundice were also recorded. No statistical differences in these parameters were found between the infants of the control mothers and those of mothers taking ampicillin.[9]

Effects on lactation and breastmilk

Relevant published information was not found as of the revision date.

References

1. Lohmeyer H, Halfpap E. [Pharmacokinetic studies and clinical experiences with ampicillin during treatment of infections of the urogenital tract of the female]. Z Geburtshilfe Gynakol 1965;164:184-202.5887161 PubMed
2. Pons G, Rey E. Antibiotics excretion in breast milk. Med Mal Infect 1994;24 (Special Issue 1):1088-106.
3. Foulds G, Miller RD, Stankewich JP, et al. The pharmacokinetics of subactam and ampicillin in postpartum women. In, Spitzy KH, Karrer K, eds. Proc 13th Int Congress Chemother 1983;1:23/17-23/22.
4. Amiraslanova LA, Emel'yanova AI, Fursova SA, et al. Some aspects of ampicillin, kanamycin and cefuroxim pharmacokinetics in puerperant patients with endometritis. Akush Ginekol (Mosk) 1985;10 14-7.2934996 PubMed
5. Peiker G, Schroder S. The concentration of oxacillin and ampicillin (Penstabil) in mother's milk in puerperal mastitis. Pharmazie 1986;41:793-5.3562514 PubMed
6. Zhang Y, Zhang Q, Xu Z. Tissue and body fluid distribution of antibacterial agents in pregnant and lactating women. Zhonghua Fu Chan Ke Za Zhi 1997;32:288-92.9596854 PubMed
7. Williams M. Excretion of drugs in milk. Pharm J 1976;217:219.
8. Ito S, Blajchman A, Stephenson M, et al. Prospective follow-up of adverse reactions in breast-fed infants exposed to maternal medication. Am J Obstet Gynecol 1993;168:1393-9.8498418 PubMed
9. Campbell AC, McElnay JC, Passmore CM. The excretion of ampicillin in breast milk and its effect on the suckling infant. Br J Clin Pharmacol 1991;31:230p. doi:10.1111/j.1365-2125.1991.tb05523.x