No medicine is 100% safe. The research that is carried out before a medicine is given a licence so that it can prescribed by a doctor, aim to minimise the risks to patients, however side effects that are rare can sometimes only be detected once a medicine has been marketed and used by large numbers of patients.
Drug safety (also known as pharmacovigilance), is the science of detection, assessment, understanding and prevention of side effects which allows us to understand more about the risks and benefits of a medicine.
Drug safety scientists collect and evaluate information from patients and healthcare professionals to try and identify new information about the use of medicines and any side effects experienced by patients.
Safety monitoring of medicines is a continuous process, it is performed during clinical trials when medicines are developed, once medicines are launched (also called ‘licenced’) and throughout the entire period where a medicine is available for patients to use. Individual patients and healthcare professionals are encouraged to report any side effects they experience via the Medicines and Healthcare products Regulatory Agency (MHRA)'s Yellow Card reporting scheme or directly to the company that manufacture the medicine.
Before a medicine can be prescribed by doctors it has to be approved for use in that country. New medicines in the UK have to obtain a Product Licence from the MHRA; the Product Licence number is printed on every pack of the medicine. To get a Product Licence a large amout of information has to be submitted about the medicine. This will include information about how the medicine is made, what checks are being carried out to ensure it is of high quality, what tests have been done, and the results of those tests. The document will be hundreds, or even thousands, of pages long when it is submitted.
The economic value of a medicine to a patient is estimated through health technology assessments. These assessments are undertaken by independent bodies such as the National Institute for Health and Clinical Excellence (NICE) for England and Wales, by the Scottish Medicines Consortium (SMC) and the All Wales Medicines Strategy Group (AWMSG).
During clinical trials information will have been gathered to enable the company to demonstrate that a medicine will improve the health of a patient to the extent that they can go back to work, or be able to look after themselves at home, or not have to reduce their time in hospital. This information will be analysed by health economists to give them evidence to justify the economic value of the new medicine.
In England once NICE has agreed that the medicine provides good value to the NHS and to the patient, GPs and hospital doctors should be free to prescribe that medicine for their patients. Inconsistent application of NICE guidelines has, in the past, led to 'postcode prescribing' of medicines - in other words a medicine could be prescribed in one area but not in another.
In the UK prescription medicines cannot be promoted to the public, and promotion to doctors is very tightly controlled. This is to ensure that the doctor makes the decision on which medicine to prescribe based on his judgement of which will be best for that patient, and that he is not influenced by any incentives to prescribe a particular medicine.
As well as UK and EU law, there is an ABPI Code of Practice which most pharmaceutical companies have signed up to. The ABPI Code covers the promotion of medicines for prescribing to doctors and other health professionals and the information that can be provided to the public about prescription only medicines.This ensures that pharmaceutical companies operate in a responsible, ethical and professional manner.