Color Matters: Pills And Patient Adherence

There is a certain logic that suggests patients may have a different view of a new pill used to treat an existing malady from a pill taken previously, especially if they do not resemble one another. But there was never any hard evidence to suggest that such a switch would affect adherence negatively, until now.

A new study finds that patients who take generic anti-epileptic drugs that differ in color from a previously prescribed pill are 50 percent more likely to stop taking the latest medication. Why not changes in shape? The smaller number of shape changes may not have provided enough power to find a statistically significant effect. The epilepsy meds studied displayed 37 different colors, but only four different shapes.

"Although the influence of pill appearance on patient behavior has long been a source of concern for clinicians, this is the first empirical analysis, to our knowledge, linking pill characteristics to patients' medication adherence," the study reseachers writes in the Archives of Internal Medicine (here is the abstract).

In reaching their conclusions, the researchers analyzed a national database of filled prescriptions and compared differences in shape and color when coming across a gap in patient use of a drug. They found that such gaps in filling prescriptions occurred more often when pills had a different color.

More specifically, they found 11,472 patients in the database stopped filling their prescriptions, including 27 percent who were prescribed epilepsy meds. One possible reason for this outcome is the placebo effect. The researhers note that physical attributes of pills have been linked to expectations of efficacy of both placebos and real drugs.

"Thus, changes in pill appearance may not only deprive patients of these expectations of efficacy, but potentially even have the opposite effect — a belief that the newly substituted pill will be less efficacious (the so-called nocebo effect)," they write. "Nonpersistence may result.

They note the FDA recently started rejecting generics that are larger than brand-name counterparts, due to an increased risk of choking and patient dissatisfaction, among other reasons. Consequently, they suggest it may be time to support changes in regulatory policy to require bioequivlaent brand-name and generic drugs appear the same.

In fact, two of the researchers last year wrote an editorial in The New England Journal of Medicine in which they argued that generics should resemble brand-name meds whenever possible. They noted that many patients – particularly, the elderly – become accustomed to reaching for a certain pill as part of a medication regimen.

As we noted previously, there were a few reasons for ensuring that brand-name pills were a different color and shape from generics. For one, brand-name drugmakers want patent protection; there are concerns about making easier to distribute counterfeit meds and patients might inadvertently receive a drug that was similar, but not identical to another (back story).