Itchy, watery eyes? Try watching TV

By David Phillips     
December 06, 2013

From: Magazine

Looking to master the quiet sneeze or get relief from those itchy, watery eyes? If so, consider watching television, at least long enough to catch an allergy commercial. Research by Professor Emir Kamenica, with Robert Naclerio of the Pritzker School of Medicine, and Anup Malani of the University of Chicago Law School, suggests these advertisements may improve the efficacy of drugs for some allergy sufferers.

Pharmaceutical companies spent $4.8 billion in 2006 alone on direct-to-consumer advertising in the United States, four times more than they spent in 1996. The spending is controversial, as commercials can motivate patients to seek prescriptions for the drugs advertised, regardless of whether that’s medically necessary. Kamenica, Naclerio, and Malani wondered if the commercials cause placebo-like effects in patients.

To find out, they designed a trial to measure the impact of ads for Claritin, the top-selling antihistamine brand in the US. The researchers split 340 participants into two groups, those who tested positive to at least one common allergen and those without allergies. They injected all of the participants with histamine to induce an allergic reaction, which occurred whether or not a person had previously tested positive for an allergy. Having done that, the researchers gave each participant a 10-mg tablet of Claritin.
Placebo effect chart
In both groups, half of the participants were randomly assigned to watch a movie spliced with Claritin ads, while the other half watched the same movie spliced with ads for Zyrtec, a competing antihistamine. After the movie, the researchers asked each participant to rate his or her perceived efficacy of Claritin. The researchers also measured the efficacy of the drug in each participant by measuring the allergic reaction. They compared the results to answers and measurements taken before the movie was shown.

Among subjects with a history of allergies, the researchers found no statistically significant change in Claritin’s efficacy or in the belief of its efficacy. However, among people without allergies, the people who had watched Claritin ads reported an increased belief in Claritin’s effectiveness at eliminating allergy symptoms. They increased their belief substantially more than those who had watched Zyrtec commercials.

When the researchers measured allergic reactions, they saw that people who had watched Claritin ads had smaller areas of swelling than people who had watched Zyrtec ads.

The researchers hypothesize that allergy sufferers had previous experience with Claritin so already knew it was effective at treating allergy symptoms. Nonallergy sufferers didn’t have prior experience with the drug.

The observed results support the view “that television advertising can impact the physiological efficacy of a branded drug, at least in subpopulations of consumers whose beliefs about the drug’s efficacy are sufficiently malleable,” the researchers write.

This may be particularly relevant for new allergy sufferers. They, like the most affected participants in the study, feel the physical effects of allergies but don’t have prior experience with allergy medications. As new allergy sufferers account for up to 15% of all patients using antihistamines, this group may appreciate the results, especially if their runny noses subside after a dose of Claritin and an evening in front of the TV.

Work cited

Emir Kamenica, Robert Naclerio, and Anup Malani, “Advertisements impact the physiological efficacy of a branded drug,” Proceedings of the National Academy of Sciences, August 2013.