Advertisements by Drug companies that directly target customers do not always translate into big sales, reports a new study carried out in Canada.

The results of the research were published in the online version of British Medical Journal. It reported that despite the multi-billion advertisement campaigns carried out by drug companies, the final impact on drug sales is at best moderate. According to an estimate in 2005, the pharmaceutical industry in the US spent around $5 billion every year in direct-to-consumer campaigns.

The study was carried out in Canada where the English-speaking provinces are exposed to drug advertisements from US media. The study thus compared drug sales in the English-speaking Canadian provinces to sales in French-speaking provinces. Prescription statistics, based on data provided by IMS Health Canada, were followed over a five year period. The results showed while the sales of two drugs, Enbrel and Nasonex, did not vary, sales of Zelnorm peaked by 40% in the English-speaking Canadian areas ever since the advertisement campaign began. However the impact was short-lived and a few years later, sales patterns in both regions became identical.

United States and New Zealand are the only two nations where direct-to-consumers drug advertisements are legal.