I must admit that off-label prescribing - prescribing drugs to treat a condition for which they were not specifically designed or tested - has always worried me. It's not that I doubt the goals of physicians to help patients, nor the fact that their pathophysiological and pharmacological knowledge goes well beyond mine. I think I worry more about the lack of controls over this practice; the seemingly Macgyver nature of the practice.

To be released to market, a drug must pass a rigorous - some say too rigorous, others say not enough - panel of clinical trials to determine everything from safety profiles to effective dose. Off-label prescription, however, does an end-run around this process. In effect, the prescribing physician has set up his or her own private clinical trial; a trial that does not have the guidance of a medical review board or governmental agency. Instead, the trial is based purely on the experiences and judgement of the prescribing physician.

Given this lack of regulatory oversight, I was surprised recently to hear that Dr. Scott Gottlieb, Deputy Commissioner for Medical and Scientific Affairs at the FDA, was in favour of off-label prescribing, offering his views on its merits at the Windhover FDA/CMS Summit in December.

"Some people believe that patients should be treated only according to the clinical evidence included in a drug's approved indications," he says. "Yet this evidence may be two or maybe three years old, especially in a fast-changing field like cancer, where off label use of medicines provide important opportunities for patients to get access to the latest clinical practice and for doctors to tailor their patients' treatment plans based on medical need and personal preferences."

"In the end, it is very hard for us here in Washington to anticipate and understand everything that goes on in a doctors' office, when patients are confronted with hard and uncertain choices," he adds. "Many decisions are guided by tiny bits of pertinent evidence, not because people prefer it that way, but because peoples' problems don't fit the clean categories that may be studied in a clinical trial."

While this may be true, I question how often the outcomes from off-label prescribing are shared publicly. Pure speculation on my part, but I suspect that the majority of off-label experiments are reported no further than a patient's medical chart. The typical physician doesn't have the time or the connections to follow-up on positive results with a drug company or medical association to launch a full-scale clinical trial. And who wants to talk about null or negative outcomes?

I'm not advocating the cessation of off-label prescribing. What I would like to see, however, is a mechanism whereby physicians can share the outcomes of this practice - positive, null, and negative - so that we can all benefit from the collective wisdom and make better informed decisions.