Pharmacogenetics
Summary and recommendations
1 People vary in their response to the same medicine. Few medicines are effective for everyone; all may cause adverse reactions or occasionally death. Some of the variation between individuals in response to medicines is due to differences in their genetic make-up. There are many different reasons why medicines may be dangerous or ineffective, such as inaccurate prescribing, poor compliance by the patient and interaction between a particular medicine and other substances, including other medication. However, advances in genetic knowledge may enable us to take better account of differences between individuals. Pharmacogenetics is the study of genetic variation that affects response to medicines. It has the potential to play an important role in improving safety and efficacy. Adverse reactions to medicines have significant costs, in both human and monetary terms. In addition, considerable resources are wasted on prescribing medicines that have little or no effect in particular patients.
2 The option of using genetic information to predict response to medicines has led some to make the optimistic claim that the development of ‘personalised’ medicine, or ‘the right medicine, for the right patient, at the right dose’, is only a matter of time. Such claims require careful assessment. Pharmacogenetics does have the potential to improve the quality of patient care significantly. Just how quickly and effectively this technology can be deployed is unclear. There are few current applications of pharmacogenetic testing, and we do not know to what degree possible applications of pharmacogenetics can be realised in practice. Several different factors will influence the proportion of patients who will come to benefit from pharmacogenetics, not least the constraints imposed by the complexity of human responses to medicines.
3 As with any new technology, the benefits of pharmacogenetics may be accompanied by unintended negative consequences. For example, the introduction of pharmacogenetics could lead to a further stratification of the market for medicines, discouraging pharmaceutical companies from developing medicines that would provide a significant benefit to only a small number of patients. The application of pharmacogenetics might impede healthcare delivery, by taking up too much of clinicians’ time. It might exacerbate existing inequities in medical provision. The extensive acquisition of genetic information that a wide-ranging programme of pharmacogenetics would involve might also lead to violations of legitimate expectations of confidentiality and privacy, and to unfair discrimination.
4 This Report considers ethical, legal and regulatory issues that may be raised by developments in pharmacogenetics, and makes a number of recommendations aimed at obtaining the greatest benefit from the potential of pharmacogenetics, while protecting the interests of patients and of society. The conclusions and recommendations made in the Report are summarised here. The nature of pharmacogenetic information
5 There has been considerable debate about the implications of genetic testing. This might be taken to suggest that genetic tests are categorically distinct from medical tests that do not concern DNA, and that they therefore raise different ethical issues. Such a view has been called ‘genetic exceptionalism’. In our view, there is no reason to assume that genetic information, including pharmacogenetic information, is qualitatively different from other medical information. The nature of the information provided by a medical test is the key to considering its implications, not whether the test involves genetic data (paragraphs 1.8-1.11). We accept that genetic tests can be rich in information and particularly significant for that reason. However, it is important to realise that the same may be true of non-genetic tests.