Last week, two important medication safety studies were published that merit attention. The first study was performed in Australia and published in the journal Pediatrics. It revealed that babies whose mothers consumed alcohol during breastfeeding had decreased cognitive abilities later in childhood when compared with children whose mothers did not consume alcohol during the same period.

The researchers examined over 5,000 children and demonstrated a convincing trend that the more alcohol the women consumed the lower their children's performance on tests designed to measure intelligence and vocabulary.  The scores were lowest when the children were tested at age 7, and the effect of alcohol seemed to disappear by the time the children turned 11 years old. The cognitive decline was not observed in children who were never breastfed, and the effect was similar whether or not the mothers also smoked during the same period.

It's important to keep in mind that this study was designed to detect an association, not a proven causation, which means that there could be other subtle and untested reasons why this particular group of children had lower test scores. Nevertheless, it's an important signal that alcohol ingested by breastfeeding infants may impair learning abilities throughout early childhood. Therefore, even minimal amounts of alcohol ingestion by mothers who breastfeed should be discouraged.

How safe is it for breastfeeding mothers to take medications? Nearly all medications taken by nursing mothers will transfer into their breast milk, but in such small concentrations that they are unlikely to cause an adverse effect on the baby. However, there are some exceptions, so mothers who take medications and who plan to breastfeed their infants should consult their healthcare professional first.

The second notable study comes from the University of Sussex in England, where researchers attempted to determine factors that cause harm from medications in people over age 65 who were recently discharged from the hospital. Over 1,000 patients, with a median age of 82, were followed for up to eight weeks after their hospitalization. Of those, 73 percent experienced medication-related harm that resulted from adverse drug reactions or failure to take their medications as prescribed. The researchers discovered that lower socioeconomic status was a main determinant of whether or not the patients took their medications as prescribed.

This study adds to an already known large body of literature indicating that elderly patients who are also relatively poor are a vulnerable group that require assistance and supervision to ensure compliance with their medication regimens and then monitored carefully for medication-related harm. These patients should be closely supervised by their physicians, nurses, and immediate family members to assure that they adhere to their prescribed medication regimen.

Ronald S. Litman, D.O., the medical director of the Institute for Safe Medication Practices, based in Horsham, Pa., and an anesthesiologist at the Children's Hospital of Philadelphia. The views and opinions expressed in this article belong solely to the author, and not necessarily to the author's employers or their affiliates. Follow him on Twitter at @DrRonLitman.