The placebo effect: plugging the nostrils of unmet needs.

Many common treatments for rhinitis symptoms are inadequate or ineffective. This may be in part because the drug does not address the pathologically altered mechanism of the rhinopathy. Objective measures may not detect treatment effects, or the treatment end points may be only subjective in nature. In many cases, these issues have not arisen because of potent placebo effects. Understanding the psychological, pharmacologic, and physiologic components of placebos is important for separating true treatment effects from those of the excipients in the vehicle. Separating the wasteful and potentially harmful effects of those excipients from the harmless and often partially beneficial effects on temporary symptom control is an important issue in clinical pharmacology that can aid in effective clinical trial design, use of objective and subjective test measures, and development of drugs to treat rhinitis.