Before a medicine is marketed, any experience of its safety and efficacy is limited to its use in clinical trials. However, the conditions under which patients and medicines are studied in clinical trials do not necessarily reflect the way the medicines are used in hospitals or general practice once they are marketed. For example, at the time of its licensing, a medicine will only have been tested in a relatively small number of patients for a limited length of time.
Despite the extensive research in animals and clinical trials in humans for a specific medicine, some adverse reactions may not be seen until a very large number of people have received the medicine. Therefore it is vital that the safety of all medicines is monitored throughout their marketed life - this is known as pharmacovigilance.
What is pharmacovigilance?
Pharmacovigilance is the process of:
- Monitoring the use of medicines in everyday practice to identify previously unrecognised adverse effects or changes in the patterns of adverse effects
- assessing the risks and benefits of medicines in order to determine what action, if any, is necessary to improve their safe use
- providing information to healthcare professionals and patients to optimise safe and effective use of medicines
- monitoring the impact of any action taken.
Risks and benefits of medicines
For a medicine to be considered safe, its expected benefits should be greater than any associated risks of harmful reactions. All medicines can cause reactions; however, it is important to note that most people take medicines without suffering any serious side effects. The patient information leaflet accompanying a medicine, which is also available from your pharmacist, will list all of its known associated side effects. Healthcare professionals such as doctors and pharmacists can also provide this information. Please see our Side effects of medicines section for further information.
How do we monitor the safety of licenced medicines?
Information sources used for pharmacovigilance
Information from many sources is used for pharmacovigilance. These include:
- spontaneous adverse drug reaction (ADR) reporting schemes, for example, the Yellow Card Scheme
- clinical and epidemiological studies
- worldwide published medical literature
- pharmaceutical companies
- worldwide regulatory authorities
- morbidity and mortality databases.
Other information sources are used to confirm, characterise and assess the frequency of the reported adverse reactions.
Information from all of these sources is carefully screened and may identify unexpected side effects, indicate that certain side effects occur more commonly than previously believed, or that some patients are more susceptible to some effects than others. Such findings can lead to changes in the marketing authorisation of the medicine, such as:
- restrictions in use
- changes in the specified dose of the medicine
- introduction of specific warnings of side-effects in the product information.
Spontaneous adverse drug reaction reporting schemes
Spontaneous adverse drug reaction (ADR) reporting is an important method for post-marketing surveillance of medicines and is vital for maintaining drug safety. The MHRA and Commission on Human Medicines (CHM) run the UK's spontaneous ADR reporting scheme - called the Yellow Card Scheme which receives reports of suspected adverse drug reactions from healthcare professionals and patients and provides an important early warning of adverse effects to medicines.
Patients
Patients, carers or parents can use the Yellow Card Scheme to report any side effects they have experienced from a medicine, and individuals can use it to report any side effects on behalf of a child or adult in their care.
Patient reporting of suspected adverse drug reactions
Healthcare professionals
For new medicines (which are labelled with a black triangle symbol on all product information and advertisements [▼]), health professionals are urged to report all suspected adverse reactions. For established medicines, health professionals are requested to report only serious suspected adverse reactions.
Healthcare professional reporting of suspected adverse drug reactions
Information collected through the Yellow Card Scheme is an important tool in helping the MHRA and CHM monitor medicine safety. Yellow Card reports of suspected ADRs are evaluated, together with additional sources of evidence such as worldwide literature, in order to detect previously unidentified hazards or side effects.
If a new side effect is identified, information is carefully considered in the context of the overall side effect profile for the medicine, and how it compares with other medicines used to treat the same condition.
Please see our How we monitor the safety of medicines section for further information.
Regulatory actions to minimise risk
When necessary, we may take action to ensure that a medicine is used in a way which minimises risk, and maximises benefits to the patient. Such action may include;
- changes to warnings in the product information or on the package label
- restricting the indications for use of a medicine
- changing the legal status of a medicine, for example, from over-the-counter to prescription only
- in rare circumstances, removal of the medicine from the market, if the risks of a medicine are found to outweigh the benefits.
The MHRA works closely with other EC regulatory authorities on pharmacovigilance matters.
Communication with healthcare professions and patients
The MHRA recognise that communication with health professionals and patients both to warn about adverse effects and to provide feedback of information is an important aspect of pharmacovigilance. We provide feedback through;
- Updating patient information leaflets (PILs) and Summaries of Product Characteristics (SPCs) for medicines when new safety issues are identified
- Letters are sent to all doctors and pharmacists by post or electronic cascade highlighting urgent warnings about drug hazards
- Publication of safety information in our drug safety bulletin ‘Drug Safety Update’ – the latest advice for medicines users. Our monthly bulletin Drug Safety Update contains the latest advice for safer use of medicines and is available on our website at 'Drug Safety Update'. If you are a healthcare professional and would like to receive a notification of each new bulletin, please send your email address to registration@mhradrugsafety.org.uk
- Fact sheets on major safety issues, which are produced for both healthcare professionals and patients
- Safety alerts are published on the MHRA website.
