Direct-to-consumer advertising of prescription drugs seems to increase the likelihood that physicians will prescribe those drugs, according to a study in the April 27th issue of the Journal of the American Medical Association. This can have mixed results in patient care, averting underuse in some cases and promoting overuse in others.

To ascertain the effects of patients’ requests influenced by direct-to-consumer advertising, Dr. Richard L. Kravitz, of the University of California, Davis, and colleagues used “standardized patients,” actors trained to present at primary care physicians’ offices with symptoms consistent with one of two conditions,  major depression or adjustment disorder.

The standardized patients, who were all nonobese, middle-age women, requested a brand-name medication (Paxil), made a general request for antidepressant treatment, or made no request at all. Altogether, the patients made 298 visits to 152 physicians between 2003 and 2004.

In the major depression visits, in 80 of 149 visits (54 percent) antidepressants were prescribed. Rates of antidepressant prescribing were 53 percent in the brand-specific group, 76 percent in the general request group, and 31 percent in the group making no request. Paroxetine (Paxil) was prescribed in 3 percent of cases, except for the 27 percent of cases where Paxil was requested by name.

Treatment considered “minimally acceptable” - antidepressant prescription, mental health referral or follow-up within 2 weeks - was administered to 90 percent to 98 percent of those who suggested medication, versus 56 percent of those making no suggestion.

Among the patients presenting with symptoms of adjustment disorder, for whom the authors note antidepressant medication is not generally indicated, the drugs were prescribed in 51 out of 149 visits (34 percent). This included 55 percent of those asking for Paxil, 39 percent of those making a general request, and 10 percent of those making no request.

“These results send a clear message that direct-to-consumer advertising is an effective but extremely blunt instrument,” Kravitz said in an interview with Reuters Health.

“The impact of direct-to-consumer advertising and requests associated with it are likely to be most positive when the condition is very serious and treatment is very effective and very safe,” he suggested.

“For example, use of cholesterol-lowering agents or aspirin in people who’ve had Heart attack or Stroke; the drugs have a long track record and they’re likely to be both effective and safe in delivering benefits to those patients.”

However, results of direct-to-consumer are “likely to be most negative when the condition is trivial and treatment is either ineffective or relatively dangerous,” he added, as in cases of baldness, toenail fungus or overactive bladder, where “the effectiveness of the drugs, if not questionable is at least marginal and there are significant safety concerns in some cases.”

He suggests “the FDA do what it can to encourage that ads be more heavily laden with education, especially around symptoms of important conditions and the treatment options, including nondrug therapy.”

If companies are unwilling, he says a tax or surcharge on direct-to-consumer advertising should be considered to pay for balanced public service announcements that incorporate evidence-based medicine.

Dr. Matthew F. Hollon, at the University of Washington in Seattle, concurs with Kravitz’s advice and goes one step further. “Because the safety of a new drug cannot be known with certainty until it has been on the market for several years, and since drug withdrawals occur more than two thirds of the time within 3 years of release,” he recommends “the FDA should consider a moratorium on advertisement of drugs directly to consumers for 3 years after initial market release.”

SOURCE: Journal of the American Medical Association April 27, 2005.