Analysis of Inventory Management Strategies and System-Level Models for Mitigating Drug Shortages in Narcotic and Psychotropic Substance Supply Chains : A Scoping Review with Health Policy Implications

Abstract

Objective: To identify and synthesize inventory management strategies and modeling approaches for mitigating drug shortages, and to determine appropriate models for understanding, simulating, and analyzing drug shortages in narcotic and psychotropic substance (NPS) supply chain as a complex system. Methods: A structured search was performed following Arksey and O’Malley’s five-stage framework and the PRISMA-ScR guidelines across four electronic databases including PubMed, Web of Science, ScienceDirect, and IEEE Xplore. The articles published during 2000 and 2024 were retrieved. The inclusion criteria covered peer-reviewed studies in English that focused on strategies, models, or technologies for managing drug shortages. Out of 4,202 records, 29 studies met the eligibility criteria for detailed analysis. Results: The scoping review identified four major thematic clusters in 29 studies for drug shortages in pharmaceutical supply chains. The largest thematic cluster was digital transformation and technology adoption. The most commonly reported cluster was identified in 17 studies (58.6%), followed by management strategies and optimization in 8 studies (27.6%). System analysis and modeling approaches were identified in 7 studies (24.1%), while policy, governance, and risk management appeared in 6 studies (20.7%). Traditional inventory management techniques, such as safety stock policies and ABC-based analyses, were commonly applied but demonstrated limitations when used in isolation within highly regulated contexts. Digital technologies primarily function as enabling tools, improving visibility and coordination. In the literature, system dynamics modeling has been recognized as particularly suited for analyzing feedback-dependent and delayed regulatory systems, while optimization or visibility-enhancing technologies usually work with fixed policy parameters. These are all significant components of highly regulated NPS supply chains. Conclusions: The study characterizes drug shortages in NPS supply chains as complex regulatory system challenges rather than merely logistical issues and approaches modeling methodologies through a perspective of system complexity. The study also highlights methodological, policy, and contextual factors specific to NPS systems in developing countries. Integrating inventory management with regulatory systems analysis establishes a foundation for more comprehensive, policy-oriented modeling frameworks.