PolyPill- Treating the Healthy

 PolyPill was an idea conceived by two professors: Nicolas Ward and Malcolm Law in 2001. The idea was simple. On pill, taken once a day by all people over 55, all diabetics over 35 and all people with cardiovascular disease, containing a mixture of drugs and vitamins could be a cheap and easy solution to reduce the risk  (according to their research) of ischaemic heart disease (IHD) by 88% and strokes by 80%¹. They claimed that such a pill, which they called PolyPill, would have “a greater impact on the prevention of disease in the western world than any single intervention.

 Whilst the concept is easy to understand the exact composition and research for the PolyPill is more complicated. The trial Ward and Law used to justify their idea di not take people give them a pill containing a drug-vitamin mix and then record how many suffered from IHD and strokes. Rather the study looked was a meta-analysis. It looked at all previous research into the drugs they were interested in and cleverly linked them together.  IHD and strokes are not like a broken bone or a pathogenic disease in that they have a single obvious cause. Both are related to a number of risk factors. Having high levels of such risk factors would not mean you would get IHD or strokes it would only be more probable. There are similar difficulties in trying to persuade smoker of the link between smoking and lung cancer. All smokers will know one lucky sod that smoked for years without developing cancer and forget the large numbers of people who unfortunately do.

 Previous trial targeted people at risk of developing IDH due to being on the extremely high or low end of one one risk factor distribution and tested to see if they could reduce the number of people developing IHD by using a drug that is designed to return that single risk factor to within normal limits. What Ward and law did was to suggest that if all these drugs were taken together in one pill it could return all known risk factor to normal limits and have a significant effect on the majority of people not just people in the extreme ends of one risk factor distribution.
 The suggested ingredient of a PolyPill would be:

• A number of drugs to reduce blood pressure (a significant risk factor of IHD) such as: 

1.  a diuretic (a chemical that increases the excretion of fluid from the body via the kidney nephrons
2.     a beta-blocker (a drug that reduces the effect of the hormones epinephrine and norepinephrine (see my post on Brunner’s syndrome))
3. an ACE inhibitor ( a chemical that inhibits the enzyme angiotensin-converting enzyme (ACE) which is part of the blood pressure regulating system. The net result is a reduction in blood volume and therefore a reduction in blood pressure)

How ACE Inhibitors work

• A statin which is a drug that reduces blood cholesterol levels by inhibiting the enzyme HMG-CoA reductase thus slowing a chain of metabolic reactions leading to cholesterol production.
• Aspirin, which among other things reduces clot formation by inhibiting the production of thromboxane a chemical that binds platelets together.  
• Folic acid, a vitamin that among other things, reduces the levels of the non-protein amino acid Homocystiene in the blood.

a Folic acid molecule

Homocystiene: Like cysteine but with an extra methyl group 

The advantages of PolyPill are that it could significantly reduce the human and financial cost of IHD and strokes which are together responsible for a third of all deaths in western countries. The pill helpfully contains ingredients that cannot be patented by drug companies so it could be made as cheaply a 10p for one daily pill. (this does however explain why drug companies have been unwilling to fund trial into PolyPill despite its huge potential benefits).

 PolyPill has not gone without criticism however. Ignoring entertaining but pretty irrelevant satire such as proposals for a PolyMeal² (a daily meal containing a small number of healthy ingredients such as almonds, garlic and fruit) the concept has also come under considerable criticism about some of the contents (it appears homocystine which the folic acid is there to reduce has only a correlative role not a causative role in IHD so the folic acid will not reduce IDH just make the blood tests look better) and because it appears Ward and law were too enthusiastic in describing PolyPill as a solution to preventing IHD and strokes (primary prevention) not preventing existing conditions of the early stages of IHD developing to the stage where it causes significant morbidity (secondary prevention). Also bear in mind that the drugs in PolyPill are not without risk. Ward and Law admit that 8-15% of people may experience some side effect.

 But PolyPill has come under most criticism for discouraging people from taking care of dietary and social risk factors associated with IHD. Why have a moderate alcohol intake, healthy diet and lots of exercise if there is a pill to do it for you? It worries me that PolyPill may become a danger to public health by medicalizing your chemical intake and distracting from simple causes of disease however much I like the idea for its simplicity and apparent efficiency. 

1-Wald NJ, Law MR. A strategy to reduce cardiovascular disease by more than 80%. http://www.bmj.com/content/326/7404/1419.full

2- PolyMeal- http://www.ncbi.nlm.nih.gov/pubmed/15604180