History of DSRU

Post-marketing surveillance (PMS) of new drugs is imperative to quantify common adverse drug reactions and to identify rare adverse reactions. The whole ethos of drug safety monitoring or ‘pharmacovigilance’ as it is known today, came into being through the tragedy of thalidomide.


This disaster of the early 1960s produced an estimated 10,000 deformed babies in the countries in which the drug thalidomide was widely used in early pregnancy. This disaster led directly to the establishment in Europe of the modern drug regulatory mechanisms. In the UK these mechanisms were first enacted into law by the Medicines Act, 1968. Even before this Act was implemented it was officially recognised that no drug which is pharmacologically effective is entirely without hazard and not all hazards can be known before a drug is marketed.

Following the thalidomide tragedy, a Committee on Safety of Drugs was established, later renamed the Commission on Human Medicines (CHM). Its task was to identify problems relating to pharmaceutical substances, to assess their toxicity and report the findings to prescribers and patients. The CHM today monitors adverse drug reactions (ADRs) by way of a spontaneous reporting mechanism known as the ‘Yellow Card’ scheme managed by the Medicines and Healthcare products Regulatory Agency (MHRA), the UK licensing authority.

DSRU established in 1980

Formerly known as the Drug Surveillance Research Unit, the Drug Safety Research Unit (DSRU) was founded in 1980 by Professor William Inman, one of the earliest contributors to post marketing surveillance and the person responsible for developing the yellow card system. Although spontaneous reporting systems have many real advantages, he recognised their limitations and as a result Professor Inman established the DSRU and devised a method for the early detection of potential drug hazards known as Prescription-Event Monitoring (PEM), which he based on ‘Event Monitoring’ (Finney D.J. The design and logic of a monitor of drug use. J. Chron. Dis. 1965, 18:77). Initially, having received an initial grant from the Office of the Chief Scientist together with unconditional pledges from the pharmaceutical industry, the DSRU was part of the Faculty of Medicine at the University of Southampton. However in 1986, it was reconstituted as a registered independent charity (No. 327206), changing its name to Drug Safety Research Unit because of the emotive connotation of the word ‘surveillance’.

DSRU no longer conducts PEM studies

In the late 1990s, a new version of PEM was developed, known as Modified PEM, or M-PEM, which enabled greater flexibility in the data requested from prescribers. Standard PEM studies were gradually phased out over the subsequent decade, such that the DSRU now conducts M-PEM studies, but not standard PEM studies. In 2009 the methodology was further modified to allow studies to be conducted in secondary care using Specialist Cohort Event Monitoring (SCEM).

The DSRU now operates as an Associated Department of the School of Pharmacy and Biomedical Sciences at the University of Portsmouth. The unit has run training courses in pharmacovigilance since 2000, under the auspices of DSRU Education and Research Ltd. A postgraduate programme in Pharmacovigilance, offered in association with the University of Portsmouth, was launched in September 2010.

There is a particular irony in that the building the DSRU inhabits today, Bursledon Hall, was once a children’s hospital where some of the worst cases of thalidomide were cared for in order to provide parental respite.