In the 80s we all had personal stereos, by the 90s we had moved on to personal trainers. Could the naughties herald the coming of personal medicines?

In America this June, The Food and Drug Administration (FDA) approved a drug called BiDil for the treatment of heart failure in self-identified black patients, representing a step toward the promise of personalized medicine.

The marketing of BiDil has been at the centre of recent debates in the US, UK and elsewhere about the role and significance of ethnicity in medical research and clinical practice. The claims of its manufacturers that the drug works better in African-Americans as opposed to other racial or ethnic groups have raised a number of issues about commercial forces and inequalities in the development of pharmaceuticals.

Dr Saggar says this sort of drug prescription by race is a very crude way to personalize medical treatments. It assumes that the drug will be effective for all black patients but will be ineffective for patients of other ethnic origins. He explains that the way the drug works, things are not this simple. BiDil is not a new drug. In fact it is a combination of two different drugs used in the past to treat chest pain (angina) and high blood pressure. BiDil was marketed before as a heart-disease treatment, but proved to be ineffective except in a sub-group of black patients, on whom it was more effective. This group of African-American patients have lower levels of nitric oxide in their blood vessels, which made them prone to high blood pressure. The drug works by raising levels of nitric oxide in the tissue, lowering blood pressure and so reducing strain on the heart.

But this is not the cause of heart disease for all African-Americans. Dr Saggar points out that the marketing of BiDil as a black-only drug makes the assumption that all black patients have the same genetic profile. This, he says, is simply not the case in the same way as it is not true for "white" patients.

The case of BiDil is a step in the right direction towards "gene-pool" specific drugs. "At the moment," says Dr Saggar, "we are not clever enough to work out the whole genetic profile of any one patient. But we are at the point where we can test for specific genetic variations and treat for these." For example a drug called Herceptin has been developed to specifically treat a form of breast cancer caused by a mutation of the HER2 gene. The treatment only works in women who are HER2-positive by targeting tumour cells that over-express the HER2 protein.

"We are now at the point of developing 'gene-pool' specific drugs," says Dr Saggar. There are many issues about who they will benefit, how they discriminate and whether they will be marketed, but personal medicines could well be the future of medicine.

· Dr Anand Saggar is senior lecturer in clinical genetics and medicine at St George's, University of London, Jennie Pollard, is the programmes director of the Science Museum's Dana Centre.

· Dr Saggar is speaking about some of the medical and ethical issues surrounding BiDil at the Science Museum's Dana Centre on Wednesday October 5 from 7pm. The event, Segregating Medicine, is part of a series for Black History Month at the Science Museum throughout October. Tickets are free, but must be pre-booked by calling 020 7942 4040 or emailing tickets@danacentre.org.uk. For further information, visit www.danacentre.org.uk.