Abstract
Shortages of medicines and vaccines have been reported in countries of all income levels in recent years. Shortages can result from one or multiple causes, including shortages of raw materials, manufacturing capacity problems, industry consolidation, marketing practices, and procurement and supply chain management. Existing approaches to mitigate shortages include advance notice systems managed through medicine regulatory authorities, special programmes that track medicines, and interventions to improve efficiency of the medicine supply chain. Redistribution of supplies at the national level can mitigate some shortages in the short term. International redistribution and exceptional regulatory approvals may be used in limited circumstances, with the understanding that such approaches are complex and may introduce cost and quality risks. If it is necessary to prioritise patients to receive a medicine that is in shortage, evidence-based practice should be used to ensure optimal allocation. Important steps in reducing medicine shortages and their impact include identifying medicines that are most at risk, developing reporting systems to share information on current and emerging shortages, and improving data from medicine supply chains.