Methods - For ten pharmaceutical substances with the largest number of patients in the Dutch outpatient setting in 2022 we identified the marketing authorisation holders (MAHs), finished pharmaceutical product (FFP) and active pharmaceutical ingredient (API) manufacturers, indicated the commercial availability and occurrence of shortages and cascading effects, and risk factors for shortages stratified for the cause of the shortage.

Results – Of the 407 authorised medicinal products, 216 were commercially available, 59 of which faced a shortage in the Netherlands. Most shortages were part of a cascade of shortages. Four pharmaceutical substances faced a meaningful decrease in supply due to shortages involving products with a cumulative market share of 39–95%. These shortages affected 25–100% of MAHs with commercially available products. Products with shortages (n=59) more often had multiple FPP sources than those not facing a shortage (51% vs. 27%, p=0.001). Products with shortages due to manufacturing problems more frequently had multiple API manufacturers (79% vs. 54%; p=0.034) and a FPP manufacturing location in Europe (and other continents) (95% vs. 81%; p=0.050). Products with shortages were more often subject to maximum pricing (58% vs. 39%, p=0.014), which was mainly driven by shortages because of manufacturing problems.

Conclusion – Effectively preventing and mitigating medicine shortages requires minimising risks on a product’s micro level (e.g. sourcing and price policies) and on the macro level of a substance (e.g. preventing cascading effects).