People are much more likely to take preventive medicines if they're combined in one pill, an international study has found. The findings are published today in the Journal of the American Medical Association.

Taking aspirin, cholesterol-lowering and blood pressure-lowering drugs long-term more than halves heart attack and stroke recurrence. However, only about 50% of people with cardiovascular disease in high-income countries take all recommended preventive medications long-term. In low- and middle-income countries, only five to 20% do. This leaves tens of millions of people under treated.

In the first study to test the impact of a fixed-dose combination pill - called a polypill - in people with cardiovascular disease, 2,004 participants in Ireland, the UK, the Netherlands and India were randomly assigned either the polypill, or their normal combination of medicines.

After an average of 15 months' follow-up, the proportion of participants in the polypill group who were taking medications regularly was a third higher than in the group receiving usual care. The polypill group also had lower blood pressure and cholesterol measurements.

Irish author Professor Alice Stanton from the Royal College of Surgeons in Ireland (RCSI) and Beaumont Hospital Dublin, said: "We know that the majority of people who suffer a heart attack or stroke, either never take the correct protective medications, or stop taking them within a year of the event. The findings of this study suggest that providing the four drugs in a single pill is a very helpful preventive step."

Professor Stanton said the new findings dispelled several myths about the polypill. "Despite the use of older cheaper medications at fixed doses within the polypill, both blood pressure and cholesterol levels improved in those taking the polypill - this is because this group took the recommended medications more regularly. Also of importance, large numbers of the trial participants are very keen to restart the polypill, if and when it is made available."

UK author Professor Simon Thom of the National Heart and Lung Institute at Imperial College London, said: "These results show that polypills are a viable strategy for heart attack and stroke survivors. This is most relevant to the large number of high-risk individuals globally who currently don't take recommended medications long-term."

While the World Health Organisation and many others have noted the potential benefits and cost savings of such an approach for over a decade, this is the first trial to show these benefits directly. Prof. Stanton further commented that "taking aspirin, a cholesterol-lowering drug and two blood pressure-lowering drugs typically costs an Irish patient in excess of €80 per month. Use of a polypill could reduce drug costs to less than €20 per month."

Most of the patients in the study had already had a heart attack or stroke; the rest were at high risk on the basis of risk factors such as blood pressure, cholesterol and smoking.

The polypills used in the study were developed by Dr Reddy's Ltd, Hyderabad. The late Dr Anji Reddy gave the green light to the development, seeing an opportunity to provide an affordable, convenient treatment package to patients in India and elsewhere.

The study was funded by the EU's Seventh Framework Programme for Research.