Tylenol, Johnson & Johnson’s big selling painkiller, is in the news today after Swedish researchers raised questions about its active ingredient, acetaminophen (also known as paracetamol). The researchers, based at Uppsala University, found that the ingredient can cause “long-lasting” cognitive effects in young mice, including decreased learning and memory capabilities.

Paracetamol is the key ingredient also in Panadol, a similar painkiller widely marketed in the U.K. and other parts of the world. Panadol is made by London-based GlaxoSmithKline. (Disclosure: I own stock in GlaxoSmithKline.)

The study was conducted by Henrik Viberg and three others, and was published in 毒理科学, the journal of the Reston, Virginia-based Society of Toxicology.

An abstract of the study can be read 此处.

The researchers were reported yesterday urging parents to be careful in administering the drug.

As quoted in the 乌普萨拉新闻报 newspaper, Henrik Viberg commented: “This shows that there are reasons to restrict the use of paracetamol late in pregnancy and to hold back from giving the medicine to infants.”