Safety Profile of Vitamin D in Italy: An Analysis of Spontaneous Reports of Adverse Reactions Related to Drugs and Food Supplements

Vitamin D (VitD) is largely used in Italy, often inappropriately; thus, an evaluation of its safety is a crucial issue. This study analyses the adverse reactions (ARs) associated with the use of products containing VitD (VitDps) reported to the Italian National Pharmacovigilance and Phytovigilance networks. From March 2002 to August 2022, a total of 643 and 127 reports concerning 903 and 215 ARs were retrieved from Pharmacovigilance and Phytovigilance networks, respectively. Overall, 332 (29.6%) ARs were classified as serious, and the most described ones were hypercalcaemia, renal failure and tachycardia. Serious AR risk was significantly higher for subjects using more than four concomitant products (OR 2.44 [95% CI 1.30-4.60]) and VitD doses higher than 1000 IU/day (OR 2.70 [95% CI 1.30-5.64]). In Italy, there was a modest decrease in AR reporting, despite the slightly increased use of VitD during the COVID-19 pandemic. To the best of our knowledge, this is the first study describing all VitDps-related ARs observed in the Italian general population. Since underreporting is the main limitation of the safety reporting systems, the necessity to continue ARs monitoring, also using real-world data on VitDps prescription, use and outcome patterns is highlighted.

Potential Direct Costs of Adverse Drug Events and Possible Cost Savings Achievable by their Prevention in Tuscany, Italy: A Model-Based Analysis

INTRODUCTION

Adverse drug events (ADEs) may represent an important item of expenditure for healthcare systems and their prevention could be associated with a relevant cost saving.

OBJECTIVE

The objective of this study was to simulate the annual economic burden for ADEs in Tuscany (Italy) and the potential cost savings related to avoidable ADEs.

METHODS

A systematic review was performed, according to the Preferred Reporting Items for Systematic review and Meta-Analysis (PRISMA) and Meta-analysis Of Observational Studies in Epidemiology (MOOSE) statements, on observational studies published from 2006 to 2016 in MEDLINE and EMBASE, focusing on direct costs of ADEs in the inpatient setting from high-income countries. The mean probability of preventable ADEs was estimated over the included studies. The mean ADE cost was calculated by means of Monte Carlo simulation. We then extrapolated the spontaneous reports of ADEs in Tuscany, Italy in 2016 from the Italian National Pharmacovigilance Network (Rete Nazionale di Farmacovigilanza), and we assumed the same costs and preventability probability for these as obtained in the systematic review. Finally, we simulated the possible costs of ADEs and preventable ADEs in Tuscany. Three sensitivity analyses were also performed to test the robustness of the results.

RESULTS

Of 11,936 articles initially selected, 12 observational studies were included. The estimated mean [± standard deviation (SD)] ADE cost was €2471.46 (± €1214.13). The mean (± SD) probability of preventable ADEs was 45% (± 21). The Tuscan expenditure for ADEs was €3,406,280.63 per million inhabitants (95% confidence interval (CI) 1,732,910.44-5,079,664.61) and the potential cost saving was €1,532,760.25 per million inhabitants (95% CI 779,776.1-2,285,750.60). Sensitivity analyses confirmed the robustness of the results.

CONCLUSIONS

The present simulation showed that ADEs could have a relevant economic impact on the Tuscan healthcare system. In this setting, the prevention of ADEs would result in important cost savings. These results could be likely extended to other healthcare systems.

Diabetes drugs and the incidence of solid cancers: a survey of the current evidence

INTRODUCTION

The evaluation of the relationship between the use of antidiabetic drug and the occurrence of cancer is extremely challenging, both from the clinical and pharmacoepidemiological standpoint. This narrative review described the current evidence supporting a relationship between the use of antidiabetic drugs and the incidence of solid cancers. Areas covered: Data from pharmacoepidemiological studies on cancer incidence were presented for the main antidiabetic drugs and drug classes, including human insulin and insulin analogues, metformin, sulfonylureas, glinides, alpha-glucosidase inhibitors, thiazolidinediones, incretin mimetics, and sodium glucose co-transporter 2 inhibitors. The relationship between the use of antidiabetics and the incidence of solid cancer was described in strata by any cancer and by organ-specific cancer and by drug and by drug classes. Information supporting biological evidence and putative mechanisms were also provided. Expert opinion: The history of exploration of the relationship between antidiabetic drugs and the risk of solid cancers has showed several issues. Unrecognized biases and misinterpretations of study results have had important consequences that delayed the identification of actual risk and benefits of the use of antidiabetic drugs associated with cancer occurrence or progression. The lesson learned from the past should address the future research in this area, since in the majority of cases findings are controversial and confirmatory studies are warranted.