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Background: Relevant safety signals in the EU are regularly communicated in so-called 'Direct Healthcare Professional Communications' (DHPCs) or European Medicines Agency (EMA) press releases. Trends of a decrease in the use of rosiglitazone following regulatory safety warnings have been described in the US. In the EU, however, relatively little is known about dispensing patterns following DHPCs or other safety signals such as EMA press releases.Objective: The objective of this study was to analyse trends in dispensing patterns of rosiglitazone and pioglitazone following DHPCs and EMA press releases in the EU member state, the Netherlands.Methods: Data for this study were obtained from the PHARMO Record Linking System, which includes drug dispensing records from community pharmacies of approximately 2.5 million individuals in the Netherlands. Over the period 1998-2008 an auto-regressive, integrated, moving average model (ARIMA) was fitted. The DHPC letters or EMA press releases were used as determinants. Adjustments were made for publication of certain literature. Stratification was performed for dispensings prescribed by general practitioners (GPs) and those prescribed by specialists.Results: For rosiglitazone, four EMA press releases and two DHPCs were issued; for pioglitazone, one DHPC was issued. The number of rosiglitazone dispensings prescribed by GPs decreased significantly after publication of DHPCs and EMA press releases concerning the risk of macular oedema and risk of fractures (both p-values 0.001). The number of rosiglitazone dispensings decreased statistically significantly after publication of EMA press releases 2 and 3 concerning cardiovascular risks but not for EMA press release 4. Adjustment for certain publications in the literature reduced the effect of communicated safety issues on the proportion of dispensings.Conclusions: Although it is difficult to disentangle the effect of DHPCs and EMA press releases from the effect of reports published in the literature, our results suggest that prescribers may react to such safety communications. [ABSTRACT FROM AUTHOR]

Objective: Numerous studies have suggested a decreased risk of cancer in patients with diabetes on metformin. Because different comparison groups were used, the effect magnitude is difficult to estimate. Therefore, the objective of this study was to further analyze whether, and to what extent, use of metformin is associated with a decreased risk of cancer in a cohort of incident users of metformin compared with users of sulfonylurea derivatives.Research Design and Methods: Data for this study were obtained from dispensing records from community pharmacies individually linked to hospital discharge records from 2.5 million individuals in the Netherlands. The association between the risk of cancer in those using metformin compared with those using sulfonylurea derivatives was analyzed using Cox proportional hazard models with cumulative duration of drug use as a time-varying determinant.Results: Use of metformin was associated with a lower risk of cancer in general (hazard ratio 0.90 [95% CI 0.88-0.91]) compared with use of sulfonylurea derivatives. When specific cancers were used as end points, similar estimates were found. Dosage-response relations were identified for users of metformin but not for users of sulfonylurea derivatives.Conclusions: In our study, cumulative exposure to metformin was associated with a lower risk of specific cancers and cancer in general, compared with cumulative exposure to sulfonylurea derivatives. However, whether this should indeed be seen as a decreased risk of cancer for the use of metformin or as an increased risk of cancer for the use sulfonylurea derivatives remains to be elucidated. [ABSTRACT FROM AUTHOR]