Oct. 24 (Bloomberg) -- U.S. doctors regularly prescribe treatments such as vitamins, painkillers and antibiotics for their potential placebo effect, a survey found.

Almost half of the rheumatologists and internists surveyed said they prescribed pills whose benefits derive from ``positive patient expectations'' two to three times a month, Jon Tilburt from the National Institutes of Health in the U.S. said in a study published today in the British Medical Journal.

``Most say they would prescribe a sugar pill for patients with a chronic painful condition if there were evidence of placebo efficacy,'' Tilburt said in the study. ``Nearly half say they have used treatments primarily to promote positive patient expectations more than once in a month.''

Before 1960, the use of inactive substances to promote a placebo effect or to satisfy patient expectations was commonplace in medical practice, the study said. Advocates of such treatment say the effect may be one of the most beneficial therapies. Opponents say such prescriptions involve deception and violate patient autonomy and informed consent.

Tilburt and colleagues from the NIH and scientists from Harvard Medical School and the University of Chicago surveyed 1,200 internal medicine physicians and rheumatologists, doctors who commonly treat patients with chronic conditions that are difficult to manage.

Ethically Acceptable

Of the 57 percent of physicians who responded to the confidential survey, 61 percent said they believe it is ethically acceptable or even obligatory to recommend or prescribe placebo treatments.

Forty-one percent of the doctors prescribed over-the-counter painkillers and 38 percent prescribed vitamins. Thirteen percent used antibiotics and sedatives.

Only 2 percent of the doctors used actual sugar pills and 3 percent used salt water-based treatments.

``The responses to this survey suggest a preference for active placebo treatments,'' Tilburt said. ``Few physicians we surveyed recommend inert placebo treatments.''

Physicians may no longer have the ability to write a prescription for a true placebo and there's a lack of pills being marketed for such use. Doctors may also shy away from recommending inactive treatments, Tilburt said.

Most of the doctors who prescribe placebo treatments typically describe them to patients as ``a potentially beneficial medicine or treatment not typically used for their condition.'' Only rarely did they explicitly call them ``placebos,'' Tilburt said.

Benign Therapy

Doctors may believe that therapy such as vitamins or painkillers may have some chance of a benefit, or that placebos may at least help the patients feel like they are being taken care of, Tilburt said.

``Prescribing harmless treatments like vitamins or over-the- counter painkillers to promote positive expectations without full disclosure of motivations might not raise alarm bells,'' Tilburt said. ``But prescribing antibiotics and sedatives when there is no clear medical indication could have serious adverse consequences for both patients and public health.''

The study was funded by the National Center of Complementary and Alternative Medicine and the Department of Bioethics at the NIH.

To contact the reporter on this story: Chantal Britt at cbritt@bloomberg.net.

Last Updated: October 23, 2008 19:01 EDT