PDR FALLS SHORT WHEN IT COMES TO TREATING OVERDOSES.

Byline: Peter Modica Medical Tribune News Service

The ``Physicians' Desk Reference,'' or PDR, is widely considered the bible on prescription drugs in the United States. But a new study finds that the drug bible frequently gives incorrect advice on how to treat drug overdoses.

Researchers found that four out of five PDR entries on the 20 drugs involved in the greatest number of overdoses in the United States were ``deficient'' and almost half of the entries advised ``ineffective'' or contraindicated therapies, they reported in the February issue of the Annals of Emergency Medicine.

A contraindication is a factor for which a doctor should not prescribe a drug.

``Even though the PDR entries are approved by the Food and Drug Administration, following its advice in a serious poisoning case could put patients in even greater danger,'' wrote researchers led by Walter Mullen, a pharmacist at the San Francisco Bay Area Regional Poison Control Center.

The PDR includes FDA-approved drug labeling that is supplied by the manufacturers.

Thirteen of the 20 entries reviewed in the 1994 edition left out a potentially lifesaving overdose treatment, such as using sodium bicarbonate as an antidote for toxicity from the antidepressant drugs imipramine, doxepin and amitriptyline.

Four of the 20 entries advised ineffective treatments that could cause harm and three others recommended a contraindicated treatment, the researchers reported.

``For overdose treatment advice, doctors should look to a poison treatment center'' and not the PDR, said study author Dr. Kent R. Olsen.

William Ellis, executive director of the Center for Proper Medication Use, a nonprofit group in Philadelphia, agreed.

``When possible, physicians and the public should try to rely on the resources available at poison control centers,'' since they offer up-to-date overdose information, he said.

As a reference book for doctors, the PDR is ``not ideal in any sense, and people should be using better references,'' said Dr. Jerry Avorn, an associate professor of medicine at Harvard Medical School in Boston.

The researchers reported that some of the advice on the 20 drugs reviewed had not changed in over 20 years. Even with revisions made in the 1994 PDR, the ``recommendations are not significantly different from the advice given in 1973,'' they wrote.

``I think the information the authors raise is compelling enough for the FDA to take a look at the adequacy of overdose information,'' Ellis said.

``Both the FDA and the pharmaceutical industry have recently taken measures to streamline the procedure for updating official labeling, and hence the information that appears in PDR,'' said a spokesperson for Medical Economics, the Montevale, N.J.-based publisher of the PDR.

Information on several drugs mentioned in the study has been updated with revised overdose management recommendations, the spokesperson said.

When the researchers surveyed 80 physicians who consulted their San Francisco poison center during April 1996, they found that half reported using the PDR for overdose information within the previous year.