Antibiotic (Aminoglycoside)
PREGNANCY RECOMMENDATION: Human Data Suggest Risk
BREASTFEEDING RECOMMENDATION: Limited Human Data—Probably Compatible
PREGNANCY SUMMARY
Except for ototoxicity, no reports of congenital defects due to kanamycin have been located. Embryos were examined from five patients who aborted during the 11th and 12th weeks of pregnancy and who had been treated with kanamycin during the 6th and 8th weeks (1). No abnormalities in the embryos were found.
FETAL RISK SUMMARY
Kanamycin is an aminoglycoside antibiotic. At term, the drug was detectable in cord serum 15 minutes after a 500-mg IM maternal dose (2). Mean cord serum levels at 3–6 hours were 6 mcg/mL. Amniotic fluid levels were undetectable during the first hour, and then rose during the next 6 hours to a mean value of 5.5 mcg/mL. No effects on the infants were mentioned.
Eighth cranial nerve damage has been reported following in utero exposure to kanamycin (1,3). In a retrospective survey of 391 mothers who received kanamycin, 50 mg/kg, for prolonged periods during pregnancy, 9 (2.3%) children were found to have hearing loss (1). Complete hearing loss in a mother and her infant was reported after the mother had been treated during pregnancy with IM kanamycin, 1 g/day for 4.5 days (3). Ethacrynic acid, an ototoxic diuretic, was also given to the mother during pregnancy.
BREASTFEEDING SUMMARY
Kanamycin is excreted into breast milk. Milk:plasma ratios of 0.05–0.40 have been reported (4). A 1-g IM dose produced peak milk levels of 18.4 mcg/mL (5). No effects were reported in the nursing infants. Because oral absorption of kanamycin is poor, ototoxicity would not be expected. However, three potential problems exist for the nursing infant: modification of bowel flora, direct effects on the infant, and interference with the interpretation of culture results if a fever workup is required. The American Academy of Pediatrics classifies kanamycin as compatible with breastfeeding (6).
References
1.Nishimura H, Tanimura T. Clinical Aspects of the Teratogenicity of Drugs. New York, NY: American Elsevier, 1976:131.
2.Good R, Johnson G. The placental transfer of kanamycin during late pregnancy. Obstet Gynecol 1971;38:60–2.
3.Jones HC. Intrauterine ototoxicity. A case report and review of literature. J Natl Med Assoc 1973;65:201–3.
4.Wilson JT. Milk/plasma ratios and contraindicated drugs. In: Wilson JT, ed. Drugs in Breast Milk. Balgowlah, Australia: ADIS Press, 1981:79.
5.O’Brien T. Excretion of drugs in human milk. Am J Hosp Pharm 1974; 31:844–54.
6.Committee on Drugs, American Academy of Pediatrics. The transfer of drugs and other chemicals into human milk. Pediatrics 2001;108:776–89.