Practice Guidelines

AAP Updates Statement for Transfer of Drugs and Other Chemicals Into Breast Milk

Genevieve Ressel

Women commonly stop breastfeeding because of medication use and advice from a physician, according to a report from the American Academy of Pediatrics (AAP). The AAP states that this advice may not be warranted. Most drugs likely to be prescribed to a nursing mother should have no effect on milk supply or on the infant's well being. The report, titled "The Transfer of Drugs and Other Chemicals into Human Milk," appears in the September 2001 issue of Pediatrics. It includes discussions of nicotine, psychotropic drugs, silicone breast implants, and other drug therapies.

TABLE 1 Drugs with No Reported Signs or Symptoms in Infants or Effects on Lactation Acetaminophen Acetazolamide Acitretin* Acyclovir† Allopurinol* Amoxicillin Antimony* Atropine Azapropazone (apazone)* Aztreonam B1 (thiamin) B6 (pyridoxine) B12 Baclofen Bishydroxycoumarin (dicumarol) Butorphanol Captopril Carbamazepine Carbetocin Cascara Cefadroxil Cefazolin Cefotaxime Cefoxitin Cefprozil* Ceftazidime Ceftriaxone Chloroform Chloroquine Chlorothiazide Cimetidine† Ciprofloxacin Cisapride Clindamycin Clogestone Codeine Colchicine* Cycloserine Diatrizoate Digoxin Diltiazem Dipyrone Disopyramide Domperidone Dyphylline† Enalapril* Erythromycin† Ethambutol Fentanyl* Fexofenadine Flecainide* Fluconazole Flufenamic acid Fluorescein* Folic acid Gadopentetic (Gadolinium) Gentamicin Gold salts Halothane Hydralazine Hydrochlorothiazide* Hydroxychloroquine† Ibuprofen Iohexol Iopanoic acid Interferon-a* Ivermectin K1 (vitamin) Kanamycin Ketoconazole Ketorolac* Labetalol Levonorgestrel* Levothyroxine Lidocaine Loperamide* Loratadine Magnesium sulfate Medroxyprogesterone Mefenamic acid Meperidine Methadone Methimazole (active metabolite of carbimazole) Methohexital Methyldopa Metoprolol† Metrizamide Metrizoate Mexiletine Minoxidil Moxalactam Nadolol† Naproxen* Nefopam Nifedipine* Norethynodrel Norsteroids Noscapine Ofloxacin Oxprenolol Phenylbutazone Piroxicam Prednisolone Prednisone Procainamide Progesterone Propoxyphene Propranolol Propylthiouracil Pseudoephedrine† Pyridostigmine Pyrimethamine Quinidine Quinine Riboflavin Rifampin Scopolamine* Secobarbital Senna Sotalol* Spironolactone Streptomycin Sulbactam Sumatriptan Suprofen Terbutaline Terfenadine Thiopental Ticarcillin Timolol Tolmetin Trimethoprim/ sulfamethoxazole Triprolidine Valproic acid Verapamil Warfarin Zolpidem NOTE: It is emphasized that many of the literature citations concern single case reports a or small series of infants. *--No mention in the literature of clinical effect on the infant. †--Drug is concentrated in human milk.

The current AAP statement is intended to update the list of agents transferred into breast milk and describe possible effects on the infant or lactation, if any are known (Tables 1 and 2).

TABLE 2 Maternal Medication Having Effects on Infant or Lactation* Drug Reported signs or symptoms Alcohol (ethanol) With large amounts, drowsiness, diaphoresis, deep sleep, weakness, decrease in linear growth, abnormal weight gain; maternal ingestion of 1 g per kg daily decreases milk ejection reflex Aspirin (salicylates) † Metabolic acidosis (one case) Atenolol† Cyanosis; bradycardia Barbiturate Should be given with caution; blood concentration in the infant may be of clinical importance Bendroflumethiazide Suppresses lactation Bromide Rash, weakness, absence of cry with maternal intake of 5.4 g per day Caffeine Irritability, poor sleeping pattern, excreted slowly; no effect with moderate intake of caffeinated beverages (2 to 3 cups per day) Carbimazole Goiter Chloral hydrate Sleepiness Chlorthalidone Excreted slowly Cisplatin Not found in milk Contraceptive pill with estrogen/progesterone Rare breast enlargement; decrease in milk production and protein content (not confirmed in several studies) D (vitamin) Follow up infant's serum calcium level if mother receives pharmacologic doses Danthron Increased bowel activity Dapsone Sulfonamide detected in infant's urine Dexbrompheniramine maleate with d-isoephedrine Crying, poor sleeping patterns, irritability Estradiol Withdrawal, vaginal bleeding Ethosuximide Drug appears in infant serum Fleroxacin One 400-mg dose given to nursing mothers; infants not given breast milk for 48 hours Indomethacin Seizure (one case) Iodides May affect thyroid activity; see iodine Iodine Goiter Iodine (povidone-iodine, e.g., in a vaginal douche) Elevated iodine levels in breast milk, odor of iodine on infant's skin Isoniazid Acetyl (hepatotoxic) metabolite secreted but no hepatotoxicity reported in infants Lithium† One third to one half therapeutic blood concentration in infants Methyprylon Drowsiness Morphine Infant may have measurable blood concentration Nalidixic acid Hemolysis in infant with glucose-6-phosphate dehydrogenase (G6PD) deficiency Nitrofurantoin Hemolysis in infant with G6PD deficiency Phenobarbital† Sedation; infantile spasms after weaning from milk containing phenobarbital, methemoglobinemia (one case) Phenytoin Methemoglobinemia (one case) Sulfapyridine Caution in infant with jaundice or G6PD deficiency and ill, stressed, or premature infant Sulfisoxazole Caution in infant with jaundice or G6PD deficiency and ill, stressed, or premature infant Tetracycline Negligible absorption by infant Theophylline Irritability Thiouracil Drug not used in the United States Tolbutamide Possible jaundice *--It is emphasized that many of the literature citations concern single case reports or small series of infants. †--Blood concentration in the infant may be of clinical importance and should be given to nursing mothers with caution.

Before prescribing drugs to lactating women, the AAP recommends that the following should be considered:

• Is drug therapy necessary? If drugs are required, the safest drug should be chosen.
• If there is a possibility of risk to the infant, consideration should be given to measurement of blood concentrations of the drug in the nursing infant.
• Drug exposure to the nursing infant may be minimized by having the mother take the medication just after breastfeeding the infant or just before the infant is ready for a lengthy sleep period.

Physicians who encounter adverse effects in infants who have been receiving drug-contaminated breast milk are urged to document these events with the U.S. Food and Drug Administration (http://www.fda.gov/medwatch/index.html). This report should include the generic and brand names of the drug, the maternal dose and mode of administration, the concentration of the drug in milk and maternal and infant blood in relation to the time of ingestion, the method used for laboratory identification, the age of the infant, and the adverse effects.

If a pharmacologic or chemical agent does not appear in the tables, it does not mean that it is not transferred into breast milk or that it does not have an effect on the infant; it only indicates that there were no reports found in the literature.