ST. JOSEPH -- Dr. Gary Lulenski is on a crusade.

The St. Joseph allergist and nose and throat specialist is trying to let as many lay people and fellow doctors know how dangerous both allergies and some widely used sedating antihistamines can be.

"One 50-milligram dose (of Benadryl) has the same effect on driving performance as 6 to 8 ounces of alcohol," Lulenski said. "Its effect is greater than a .10 blood alcohol level."

A Michigan driver with a .10 level of alcohol in his or her blood is considered drunk and can be charged with operating under the influence of liquor.

As part of his effort to alert people, Lulenski laid out his concerns in a recent speech at the St. Joseph/Benton Harbor Rotary Club.

Lulenski told the Rotarians he is making similar presentations to hospital workers to alert them to the new studies. He is also developing a videotape on performance in the workplace under the influence of sedating antihistamines.

He said a just-completed study by Dr. Gary Kay of Georgetown University shows another common antihistamine, Chlortrimetron, at a 2-4 milligram dosage, has the same effect on mental alertness as 50 milligrams of Benadryl.

The effects include poor coordination, shortened attention span, fatigue and drowsiness. As a result, the likelihood of on-the-job and home injuries increases.

A spokeswoman for the drug manufacturer said the packaging warns users about possible drowsiness.

"It's (Benadryl) a proven, safe and effective product," said Meghan Marschall, director of marketing communications for Pfizer Consumer Group. Pfizer is the parent company of Warner-Lambert, which makes Benadryl. "We do have warning labels that say 'May cause marked drowsiness, use caution when operating a motor vehicle or operating machinery.' There are always warnings with any over-the-counter drug, and people should always read them."

She said she would have to get copies of the studies cited by Lulenski showing Benadryl's severe effects and run those past Pfizer scientists to comment adequately.

Lulenski said a recently published study of people in HMOs taking antihistamines for 30 days compared medical records of 12,000 taking diphenhydramine and 2,500 taking Loratadin, a non-sedative antihistamine. The study, by Dr. William Finkel in Los Angeles, examined six types of accidental injuries during the first month the patients took their respective medicines.

Those on diphenhydramine suffered nearly three times as many accidents at home. The injuries included burns and fractured bones.

People at work were 50 percent more likely to be injured if they were taking any of the sedating antihistamines than people who were not. And a study by the Yale-New Haven Medical Center showed brain function was so slowed, clerical workers had error rates of 67 percent in such simple operations as filing alphabetically, Lulenski said.

Lulenski said the most popular sedating antihistamine, diphenhydramine (the primary ingredient in Benadryl), "is something you should not use if you're going to be at work, drive to work or do any task that requires good concentration and attention span."

He said the most frequent dosage for adults is one 50-milligram dose every eight hours. The effects wear off slowly. Lulenski called the time that medications stay in the bloodstream "half-lives" - the time it takes for a drug's potency to drop by one-half.

"Benadryl at 50 milligrams has a half-life of about eight hours," he said. "It's about when you'd be driving to work if you took it when you went to bed."

Many people will take a second dose after eight hours, which, combined with the amount still in the body, can further impair reaction time, coordination and attention span.

"With many drugs, when there's half (the dosage) in your system, that's still a lot. We can't test people accurately for allergies with that much in the system. We have to wait 72 hours after their last dose," he said.

Asked if Benadryl was effective against bee stings, Lulenski said it is a very good antihistamine.

"We use it intravenously as the drug of choice," he said. "But since I found out about this study (the effect on driving), we don't let patients drive home after an injection. We have them sign a written agreement someone else will drive them home."