Direct to consumer advertising of prescription drugs
Canada prohibits direct to consumer advertising of prescription drugs however, US advertising is crossing the border via cable TV and US magazines.
Law et al found that cross border advertising increased prescribing of a minimally effective drug with a poor safety profile, which subsequently led to its withdrawal. They used 3 drugs based on timing of the advertising and compared prescription in English speaking areas, where they are likely to watch and read US based media, with French speaking areas, where there is less exposure.
There was a 42% increase in prescribing of tegaserod after intensive US advertising campaigns (29 574 extra prescriptions over a two year period). In a pooled analysis of 29 clinical trials, 13 of 11 614 patients treated with tegaserod had heart attacks, strokes, or serious angina compared with one of 7031 patients on placebo. Among the extra prescriptions in Canada as a result of direct to consumer advertising, around 29 people would have experienced serious cardiovascular events over the two years.
Part of the concern is the ability to shift the balance of potential benefit to harm. Tegaserod is used to treat irritable bowel syndrome. “What for many people is a mild functional disorder—requiring little more than reassurance about its benign natural course—is currently being reframed as a serious disease attracting a label and a drug.”
Editorial: BMJ 2008;337:a985
Full Article: BMJ 2008;337:a1055