If you take a study in the Journal Of General Internal Medicine at face value, the next time your doctor gives you a drug sample from her desk drawer, you will decline it, even though the sample would save you money that you and I both know you would use wisely.

Why do these authors urge caution in accepting free samples? Because, their study found, those free handouts are often not the best medications for your condition, that is, the samples doctors receive influence their prescribing habits, and doctors often substitute a sample that's at hand for another drug that would ordinarily be their first choice, a finding that will not surprise the pharmaceutical companies, of course, who spend millions of dollars giving out free samples to doctors precisely, I'm sure, because they know the samples do influence doctors into prescribing those drugs.

Now, if you take that finding at face value, it might lead you to conclude that doctors are doing you harm by giving you the wrong drugs, so before I get kicked out of my doctors' union (oops! I mean, of course, "association," not union), for seeming to pick on my fellow MDs, let me quickly state that I don't believe that the practice of dispensing free samples is detrimental to your health.

First, handing out free samples has at least one major benefit: it often does save patients money. In the free clinic where I used to practice, for example, the samples - birth control pills, antibiotics, etc. - were lifelines for some of our patients.

But more important, I think, is that handing out samples rarely causes harm because, with rare exceptions, for the great majority of problems that make up a primary care practice, substituting one product for another usually makes little difference in outcome. Why? Because, most new drugs are "me-too" products developed with only one goal in mind: to compete with a successfully marketed rival, and while these clones usually offer little advantage over the established drug (newer SSRI antidepressants such as Paxil® and Zoloft®, for example, versus the older Prozac®), they rarely offer much disadvantage either, although they do serve the valuable role of keeping drug prices down through healthier competition.