Objective: Communication of a drug's benefits and risks through drug labelling is an important tool in the risk management of prescription drugs. Contraindication labelling provides the strongest safety-based guidance for the health care practitioner. In this study, the labelling of new contraindications between the United States (US) and Germany was compared.
Methods: We assessed whether contraindications that were newly labelled in the US between January 2003 and May 2005 had been incorporated into the German Summary of Product Characteristics (SPC) by October 2005 (end of the study period). We classified the results of our comparison as no difference, a slight difference (more detailed contraindication in one country or the other) or as a relevant difference (new US contraindication not contraindicated in the German SPC). We assessed the time difference between the date of the labelling change in the US and October 2005.
Results: During the study period, 66 new contraindications were evaluable for analysis. We found no difference in labelling between the US and Germany with regard to 30 contraindications (45.5%) and slight differences with regard to 14 contraindications (21.2%). In 22 instances (33.3%), the new contraindication in the US had not been incorporated into the German SPC. The median delay between the date of labelling in the US and October 2005 was 14 months and ranged between 5 and 31 months. In 77.3% of the relevant differences in contraindication labelling, the pharmaceutical manufacturer was the same in the US and Germany.
Conclusion: Our study shows a remarkable discrepancy in the labelling of new contraindications between the US and Germany. The underlying reasons for this discrepancy were discussed, but need to be explored further.