Medications and Mothers' Milk, 9th edition
by Thomas Hale, PhD
Pharmasoft Publishing; 1999
Reviewed by Kathy Koch
Great Mills, Maryland, USA
From: LEAVEN, Vol. 37 No. 2, April-May 2001, p. 37
The 9th edition of Medications and Mothers' Milk by Dr. Thomas Hale is by far the most current and complete reference on drugs and breastfeeding presently available. It is easy to read, provides explanations of medical words, and is affordable. Updated annually, this edition brings with it the addition of 50 new drug entries and two new categories (lactation risk category and theoretic infant dose) to assist in determining the possible effects on a nursing infant of a drug taken by the child's mother.
As LLL Leaders we often receive calls and questions about taking a specific medication or herbal remedy. it is important to remember that we cannot tell a mother if it is safe for the mother or her nursling for her to take any particular medication while she is breastfeeding. Nor can we encourage her to wean her baby while taking medication or suggest any alternate medications. (See LEADER'S HANDBOOK, Revised 1998 p. 211.) These decisions rest with the mother after consultation with her health care practitioner. While keeping these limitations in mind, Leaders will find Medications and Mothers' Milk 9th edition, a valuable addition to their personal breastfeeding libraries.
As this book is written with both the lay breastfeeding counselor and the medical professional in mind, some things may be a bit difficult to understand for someone without a background in pharmacology or medicine, but Dr. Hale provides comprehensive definitions and explanations. With careful reading, LLL Leaders and members will be able to understand the terms used. Being able to explain these terms to mothers is another issue, and Leaders need to take care when giving this information to mothers that they are not "interpreting" the information in the book but rather are strictly providing the information as it appears in the book.
This book also contains listings of several factors that can influence the amount of drug secreted into human milk. Lipid solubility, molecular weight, protein binding, milk:plasma ratios, oral bioavailability, volume of distribution, and half lives are particularly useful information. This allows the Leader to provide the mother with several parameters on which to make her decision. Dr. Hale defines and explains these terms, and then explains how the clinician can apply these terms to helping situations.
A typical drug listing provides trade and generic names. This is helpful as many drugs go by more than one brand name and their inclusion makes this book useful for evaluation of medications around the world. The index is also quite thorough, listing many generic and brand names for a particular drug. The drug's typical uses are also listed.
The section on the American Academy of Pediatrics' (AAP) recommendations may be confusing for some entries. Because Dr. Hale forms his conclusions from peer-reviewed medical journal articles and unpublished studies, as well as the recommendations of the AAP, in some cases his recommendations differ from those of the AAP For example, Cimetidine (Tagamet) is listed as "approved by the AAP for use in breastfeeding mothers." Dr. Hale writes, however, that "other choices for breastfeeding mothers should preclude the use of this drug. Short term use (days) would not be incompatible with breastfeeding." Diltiazem HCl (Cardizem) is AAP-approved for use in breastfeeding mothers, but again, Dr. Hale writes that "authors recommend against using diltiazem in breastfeeding mothers."
In other cases, the drug is not AAP-approved, yet Dr. Hale has fewer concerns. For the listing on Metronidazole Vaginal Gel, the AAP classifies this drug as a "drug whose effect on nursing infants is unknown but may be of concern." Dr. Hale adds information from a study finding "plasma levels following administration are exceedingly low" and "milk levels following intravaginal use would probably be exceedingly low." Again, Lorazepam is also listed by the AAP as a "drug whose effect on nursing infants is unknown but may be of concern." Dr. Hale adds more specificity by referring to a study in which "there were no untoward effects noted in any of the infants," and concludes that "it would appear from these studies that the amount of Lorazepam provided via milk would be clinically insignificant under most conditions."
These differences in findings make it especially important for the Leader to read all information verbatim and allow the mother, in consultation with her health care professional, to draw her own conclusion.
Similarly, many entries have suggestions for alternate medication options. This is of concern because, as LLL Leaders, we are not to suggest or recommend the use of any medication. Were a Leader to read this, it could be construed as a recommendation that another medication be prescribed. LLL Leaders should take care when using this book to give the mother the exact citation of the book so the recommendation is clearly that of Hale and not the Leader.
The two new categories for this edition are Lactation Risk Category and theoretic infant dose. The Lactation Risk Category was created by Dr. Hale to assist in evaluation of medications during breastfeeding. It is similar to the more familiar Food and Drug Administration Pregnancy Risk Category and includes five categories: Ll-Safest, L2-Safer, L3-Moderately Safe, L4-Hazardous, and L5-Contraindicated. Dr. Hale provides a more detailed description of these categories in the book's introduction. Again, it is important to remember that this category is Dr. Hale's opinion and is not supported by any independent organization.
The theoretic infant dose is an estimate of the maximum possible dose an infant would receive via mother's milk. Dr. Hale calculated this number using information provided in published literature about the medications. This number is only provided for a very few entries in this edition and is intended to be used in conjunction with other data for a particular medication, not as the only determinant of a medication's appropriateness.
This is a useful and valuable reference. As with all non-LLL sources, however, LLL Leaders should use the information in Medications and Mothers' Milk, 9th edition, judiciously and wisely, taking into consideration LLL recommendations regarding questions about medications while breastfeeding.