Pharmacovigilance - how we monitor the safety of medicines

Even with 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.

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 is needed to improve their safe use;
• providing information to healthcare professionals and patients to optimise safe and effective use of medicines; and
• monitoring the impact of any action taken

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;
• information from pharmaceutical companies;
• information from worldwide regulatory authorities; and
• morbidity and mortality databases.

Information from all these sources is carefully screened.  It may identify unexpected side effects or indicate that certain side effects occur more commonly than previously believed, or that some patients are more susceptible to some problems than others. Such findings can lead to changes in the marketing authorisation of the medicine, for example:

• restrictions in use;
• changes in the dose of the medicine; and
• introduction of specific warnings of side-effects in product information.

Spontaneous adverse drug reaction reporting schemes
The MHRA and Committee on Safety of Medicines (CSM) run the UK's spontaneous adverse drug reaction reporting scheme - called the Yellow Card Scheme.  This receives reports of suspected adverse drug reactions from health professionals and patients.

Patients
If a patient, carer or parent think they or someone else has had an unwanted or harmful reaction, they should report this.

Healthcare professionals
For new medicines health professionals are urged to report all suspected adverse reactions.  New medicines are labelled with a black triangle symbol  on all product information and advertisements.  For established medicines health professionals are requested to report only serious suspected adverse reactions.

The Yellow Card Scheme provides an important early warning of adverse effects to medicines.  Other information sources are used to confirm, characterise and assess the frequency of adverse reactions.

Regulatory actions to minimise risk
Very rarely, if the risks of a medicine are found to outweigh the benefits, it may be necessary to remove the medicine from the market.  More usually, the risk of a side effect may be avoided or reduced by the following:

• including warnings in the product information or on the package label;
• restricting the indications for use of a medicine; and
• changing the legal status of a medicine, for example, from pharmacy to prescription only.

The MHRA works closely with other EC regulatory authorities on pharmacovigilance matters.

Communication with healthcare professions and patients
Communication with health professionals and patients both to warn about adverse effects and to provide feedback of information is an important aspect of pharmacovigilance. 

• Patient Information Leaflets (PILs) and Summaries of Product Characteristics (SPCs) for medicines are updated when new safety issues are identified.
• For urgent warnings about drug hazards, letters are sent to all doctors and pharmacists by post or electronic cascade. 
• The regular drug safety bulletin, 'Drug Safety Update',  produced by the MHRA and CHM aimed at all healthcare professionals.
• Fact sheets are produced for major safety issues for both healthcare professionals and patients
• Safety alerts are published on the MHRA website