Published: 1 March 2018

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The Medsafe Files — Episode Five: Pharmacovigilance

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Prescriber Update 39(1): 6-7
March 2018

Medsafe uses a variety of methods to collect information on the safety and quality of medicines and vaccines after they have been approved. These activities are known as pharmacovigilance. The main aim of pharmacovigilance is to identify emerging safety signals related to the use of medicines or vaccines or new information on known side effects.

What is pharmacovigilance?

Before a medicine is marketed, experience of its safety and efficacy is limited to its use in clinical trials. However, clinical trials do not always reflect the way a medicine or vaccine is used in real life. In addition, some populations such as pregnant women are not usually studied in clinical trials.

Although Medsafe may receive extensive information from clinical trials for a specific medicine, some adverse reactions are rare and may not be seen until a very large number of people have taken the medicine. For this reason, it is very important to continue to monitor all medicines after they have been approved.

What does pharmacovigilance involve?

Pharmacovigilance involves:

• monitoring the use of medicines in everyday practice to identify previously unknown adverse effects or changes in the patterns of adverse effects
• assessing the benefits and risks of harm of medicines to determine if action is required to improve their safe use
• providing information to healthcare professionals and consumers to promote medicines safety
• monitoring the impact of any action taken and assessing whether further action is require

Where does this information come from?

Information from many sources are used for pharmacovigilance including:

• clinical and observational studies
• published medical literature
• pharmaceutical companies
• other regulatory authorities such as the United States Food and Drug Administration (FDA), European Medicines Agency (EMA) and Australia’s Therapeutic Goods Administration (TGA).
• spontaneous suspected adverse reaction reports submitted to the Centre for Adverse Reactions Monitoring (CARM).

What are spontaneous suspected adverse reaction reports?

These are unsolicited case reports of suspected adverse reactions or adverse events that people have experienced while taking a medicine. Reports are collected by CARM in Dunedin.

Anyone can submit a report to CARM including healthcare professionals, consumers and pharmaceutical companies.

The advantages of these reports include that they are a very quick and effective way of finding potential safety signals with medicines and they can be used to monitor medicines safety in real life use over the lifetime of the medicine.

Limitations of spontaneous suspected adverse reaction reports include:

• under-reporting (ie, some cases may not be reported)
• lack of reliable information on the number of people taking the medicine
• incomplete information on diagnosis and history of the patient
• they are not very effective at detecting adverse reactions that occur a long time after starting the medicine.

Due to these limitations, spontaneous reports are generally only used to detect safety signals and are not used to investigate or confirm them. Information obtained from spontaneous reports needs to be interpreted with caution.

What is a safety signal?

A safety signal is an indication that there may be a safety problem related to a medicine. A signal could be a previously unknown adverse reaction or a change in the frequency or severity of a known side effect.

What does Medsafe do with this information?

Medsafe analyses adverse reaction reports together with other information to determine if the safety signal is real. Medsafe seeks the advice of independent experts through the Medicines Adverse Reactions Committee (MARC) or may also form working groups of experts to provide advice.

Medsafe undertakes a risk-benefit assessment on safety signals to see if any action is required.

The majority of safety signals that Medsafe investigates are not supported when all of the available information is closely examined. In this case, no action is considered necessary, although Medsafe may continue to closely monitor the issue.

A small number of safety signals are confirmed on close examination of the available information, and Medsafe takes appropriate action to improve the safe use of these medicines.

What action can Medsafe take if a safety concern is confirmed?

• Provide information directly to healthcare professionals and consumers on medicines safety issues.
• Require changes to medicine data sheets and/or the product label.
• Restrict the conditions that the medicine can be used for.
• Recommend that the legal status of a medicine is changed, for example from over-the-counter to prescription only.
• In rare circumstances, Medsafe can recommend removal of the medicine from the market.

How does Medsafe communicate with healthcare professionals and consumers?

Communication with healthcare professionals and consumers is one of the best ways to provide information about adverse effects and safe use of medicines.

Medsafe provides information by:

• requesting pharmaceutical companies to update medicine data sheets and consumer medicine information (CMI)
• publishing information here in Prescriber Update
• publishing safety alerts, media releases and consumer recalls on the Medsafe website.

You can subscribe to receive an electronic copy of Prescriber Update and alert communications on the Medsafe website (www.medsafe.govt.nz/profs/subscribe.asp).

Neither Medsafe nor CARM can say in individual cases that a medicine was the actual cause of a suspected adverse reaction. Any consumer who has concerns regarding medicines they are taking should discuss these with their healthcare professional.