Advertising of antihypertensive medicines and prescription sales in Australia.
BACKGROUND
Drug promotion is one of the main factors that influence prescribing practices, but there are limited data available to quantify the relationship between drug advertising and prescription sales.


OBJECTIVE
To investigate the relationship between advertising for antihypertensive medicines and prescription sales in Australia between 1993 and 2002.


METHODS
Retrospective observational study. Advertising trends were monitored by counting the number of advertisements published in three Australian medical journals. Monthly prescription dispensing data were obtained from Drug Utilisation Sub-Committee and expressed as numbers of defined daily doses/1000 inhabitants/day. Linear regression and cross-correlations of time series were used in the analysis.


RESULTS
The drug classes the most heavily advertised, angiotensin-converting enzyme inhibitors and calcium channel blockers, were also the most prescribed during the study period, while the drugs the least advertised, thiazide diuretics and beta-blockers, were the least used. In 5 of the 7 main antihypertensive classes, the product the most advertised was also the most prescribed. Other factors, such as the publication of large clinical trials, may have also influenced prescribing patterns.


CONCLUSIONS
Prescription sales of antihypertensives in Australia are correlated with promotional advertising. The newest and most expensive medicines may be chosen over older effective drugs by prescribers. New policies on drug promotion control need to be developed.
Vitry
A
A
Quality Use of Medicines and Pharmacy Practice Research Centre,University of South Australia, Adelaide, South Australia, Australia. agnes.vitry@unisa.edu.au
Lai
Y H
YH
D000329:Advertising / Q000191:economics* / Q000639:trends*; D000959:Antihypertensive Agents / Q000191:economics* / Q000627:therapeutic use; D001315:Australia; D011307:Drug Prescriptions / Q000191:economics*; D006801:Humans; D012189:Retrospective Studies
D000959:Antihypertensive Agents