An overdose of the active ingredients in Benadryl and Tylenol caused a student’s death in January, according to toxicology results from the Tarrant County Medical Examiner’s Office’s released this week.

The Medical Examiner’s Office Web site listed junior nursing major Amanda Bebout’s manner of death as suicide and listed the official cause of death as “acute diphenhydramine and acetaminophen intoxication.”

Bebout was found unresponsive in her off-campus residence Jan. 18.

Diphenhydramine, the active ingredient in Benadryl, is an antihistamine intended to relieve allergy symptoms, according to the maker’s Web site. Acetaminophen, the active ingredient in Tylenol, is intended to be used as a pain reliever and fever reducer, according to the company’s Web site.

Roger Metcalf, deputy public information officer for the Tarrant County District Medical Examiner’s District, said the substances could have been taken separately or in a combined form such as Tylenol PM. There are often no outward, physical signs of the intoxication, but acetaminophen intoxication would cause liver failure. Death from an overdose of these medications would take a few hours, he said.

Metcalf said he could not tell from the toxicology report exactly how many milligrams Bebout ingested or exactly which combination of the medications she took. He said these were most likely over-the-counter, and he is not aware of any prescription medications that contain both ingredients.