FDA Probing Effects of Most-Prescribed Sleeping Aid

WASHINGTON —  The Food and Drug Administration is investigating the most popular prescription sleeping pill because “a disproportionate number of adverse reactions” have been reported by people taking the drug, officials said Wednesday.

Spokeswoman Faye Peterson said that an FDA advisory panel will meet today and Friday to look into the side effects of Upjohn Co.’s Halcion, the world’s most-prescribed insomnia medication.

The meeting was called because FDA records “indicate reporting of certain adverse events . . . is greater for Halcion” than with similar medications, Peterson said.

“That increased number raises flags,” she said. She added: “There is a suggestion that certain of these (adverse reactions) are dose-related.”

Halcion’s possible side effects are known to include confusion, agitation, hallucinations and amnesia, Peterson said.

The FDA spokeswoman said there has been a lot of publicity about Halcion’s negative effects, and so it is possible that the attention prompted more widespread reporting of adverse reactions by people who used Halcion than by those taking other, similar sleeping aids.

Upjohn has discontinued production of Halcion pills in the strongest dosage, a spokeswoman at the company’s Kalamzoo, Mich., headquarters said. She also said that Upjohn’s own studies found Halcion to be no more likely to cause adverse side effects than any other medication from the same family of drugs, called benzodiazepines.