PIC QUESTION OF THE WEEK: 09/05/05 Q: What analgesics are safe to use while breastfeeding? A: Human breast milk contains nutrients, enzymes, hormones, and prostaglandins as well as growth, immunologic, and anti-allergic factors. In addition, breastfeeding also appears to provide developmental, psychological, social, environmental, and economic benefits. Some mothers may stop breastfeeding prematurely because they are taking medications. However, most women can continue to breastfeed while taking medications with minimal risk to the infant. Drugs that readily transfer into human milk characteristically have high lipid solubility, low molecular weight, limited protein binding, and are unionized. They generally pass by simple diffusion across a semi-permeable membrane. The quantity of drug in breast milk is usually determined by the concentration gradient between plasma and milk. Analgesics are frequently used for postpartum analgesia, but may subsequently be indicated for other forms of acute and chronic pain. The degree of pain is a factor in determining the choice of analgesic prescribed. For mild to moderate pain, acetaminophen or most non-steroidal antiinflammatory drugs (NSAIDs) are considered safe. Acetaminophen may produce fewer adverse effects in the infant compared to NSAIDs and has a long history of safety when used during breastfeeding. If using NSAIDs, ibuprofen is the preferred agent because of its short half-life and inactive metabolites. Naproxen is also considered compatible with breastfeeding by the American Academy of Pediatrics (AAP). There is little data regarding the safety of the non-narcotic analgesics propoxyphene and tramadol during breastfeeding. For severe pain, narcotic analgesics such as morphine, codeine, and fentanyl are considered compatible for short-term use by the AAP. Meperidine is not recommended because of the long half-life of its metabolite and possible association with neurobehavioral depression. Oxycodone levels in milk may result in the child’s absorption of nearly 10% of the therapeutic dose, thus the drug should be administered for a limited duration. Mothers who take narcotic analgesics should monitor their infants for gastrointestinal effects, sedation, and changes in feeding patterns. References: • • •
Hale TW. Medications and mothers’ milk. 11th ed. Amarillo:Pharmasoft;2004. Briggs GG, Freeman RK, Yaffe SJ. Drugs in pregnancy and lactation. 7th ed. Philadelphia (PA): Lippincott Williams Wilkins;2005. Committee on Drugs. American Academy of Pediatrics. The transfer of drugs and other chemicals into human milk. Pediatrics 2001;108:776-89.
Debra L. Pruss, Pharmacy Clerkship Student Lauren R. Vitale, Pharmacy Clerkship Student