Their report on an inexpensive test to identify fake tablets of Panadol was presented here at the 244th National Meeting & Exposition of the American Chemical Society, the world's largest scientific society.

Panadol is one of multiple brand names used abroad for the pain-and-fever-reliever acetaminophen, most familiar in the U.S. as Tylenol. The scientists emphasized that no such problem exists with Tylenol or other acetaminophen products marketed in the U.S.

However, Toni L. O. Barstis, Ph.D., a chemistry professor and leader of the research team at Saint Mary's College in Notre Dame, Ind., said that ersatz Panadol and other counterfeit brand-name acetaminophen products are the tip of the iceberg in a wider problem of fake drugs sold in developing countries.

"Panadol long has been among the most common, standard pain-relieving drugs counterfeited around the world," Barstis said. "But the problem has taken on a troubling new dimension. In the past, you could just look at the labeling and packaging and know if it was counterfeit. Now, they do such a good job with the package design it's hard to determine whether it's a package of the genuine medicine or a fake that contains no acetaminophen or even ingredients that may be harmful."