Postmarketing surveillance of new drugs: II. Case studies

Adverse Drug Reactions and the Food and Drug Administration

The monitoring of adverse drug reactions (ADRs) after a drug is marketed is an important mission for the US Food and Drug Administration (FDA). Currently, the FDA receives and computerizes nearly 60,000 ADR reports each year. The FDA has an active postmarketing surveillance system in place to effectively triage, tabulate, analyze, and evaluate these reports. Of highest priority to FDA are the discovery of serious reactions that were not observed before a drug was marketed and the detection of increased occurrence of serious reactions that are known to occur with the drug. All reactions for new moieties marketed in the United States during their first 3 years are of interest. Pharmacists are in a unique position to be aware of adverse reactions because of their knowledge of drugs, their close working relationships with other health care providers, and their direct interactions with patients. By participating in FDA's ADR reporting system, pharmacists can actively contribute to drug safety and help improve patient care.

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A 1-year cross-sectional analysis of non-interventional post-marketing study protocols submitted to the German Federal Institute for Drugs and Medical Devices (BfArM)

Purpose

The aim of non-interventional studies (NIS) with medicinal products is to investigate the use of authorized medicinal products in daily routine. In the past, this type of study has been subject to frequent criticism, and many recommendations have been published. The aim of our study was to assess the quality of NIS study protocols.

Methods

Nearly all NIS study protocols submitted to the German Federal Institute for Drugs and Medical Devices (BfArM) within a period of one year could be analyzed. The protocols were evaluated in terms of objectives, methods and included patients, as well as with regard to their compliance with quality recommendations for NIS by federal authorities and pharmaceutical industry associations.

Results

The 136 NIS available for study were scheduled to enroll approximately 330,000 patients (2,500 patients per study) and 43,000 healthcare professionals. Of these NIS, 58 % were performed with medicinal products that had been authorized within the past 5 years; however, 68 % of the investigated active pharmaceutical ingredients were older than 5 years, and 19 % were even older than 19 years. Only 56 % of the protocols provided information on publication policy, and 65 % required the involvement of ethic committees. The adherence to current quality recommendations was average, but the compliance of NIS performed by member companies of the Association of Research-Based Pharmaceutical Companies was significantly higher than that of other sponsors.

Conclusions

Current quality recommendations are still not fully implemented in most NIS protocols. Therefore, the scientific value of many NIS is still questionable, and the criticism that NIS are mainly conducted for marketing reasons could not be refuted by the data analyzed here.

Electronic supplementary material

The online version of this article (doi:10.1007/s00228-013-1482-z) contains supplementary material, which is available to authorized users.

Power and weakness of spontaneous reporting: a probabilistic approach

It has been clearly demonstrated that spontaneous reporting remains one of the best ways for picking up new adverse drug reactions (ADRs) once a drug is on the market. The probability of revealing a new ADR by spontaneous reporting was studied as a function of reporting rate, strength of drug-event association (relative risk), background incidence of the event and number of patients treated. The model included determination of (i) the probability of reporting at least one drug-event association case and (ii) the overall probability of concluding that the drug-event association is not coincidental. Both probabilities were generally low. The results suggest that the identification of a new risk by spontaneous reporting implies a strong association between the drug treatment and the occurrence of the event.

Patient-initiated postmarketing surveillance: a validation study

A new patient-initiated, pharmacy-based postmarketing surveillance system is described. At the time a new prescription for a targeted drug was filled, 2705 outpatients (experimentals) randomly assigned to the new system had a printed notice attached to their medication bags: the information requested them to report any "new or unusual symptoms" during the next 2 weeks by a toll-free telephone number to a trained nonprofessional who conducted a standardized adverse drug reaction (ADR) interview. To help validate the new system, another sample of 1109 patients (controls) did not receive a request for self-monitoring but were interviewed by telephone 2 weeks later. Target drugs were chosen from two classes for which side effect profiles are well identified: oral antibiotics and tricyclic antidepressants. Results show that within both drug classes, all patient-initiated reports closely matched those obtained from controls; the experimental and control groups also reported predictably high relative frequencies for the most commonly expected ADRs. Additional analyses suggest that a patient-initiated monitoring system could prove to be a promising complement to existing physician-based surveillance systems.