Across OECD countries, pharmaceutical spending reached around USD 800 billion in 2013, accounting for about 20% of total health spending on average when pharmaceutical consumption in hospital is added to the purchase of pharmaceutical drugs in the retail sector. This chapter looks at recent trends in pharmaceutical spending across OECD countries. It examines the drivers of recent spending trends, highlighting differences across therapeutic classes. It shows that while the consumption of medicines continues to increase and to push pharmaceutical spending up, cost-containment policies and patent expiries of a number of top-selling products have put downward pressure on pharmaceutical prices in recent years. This resulted in a slower pace of growth over the past decade. The chapter then looks at emerging challenges for policy makers in the management of pharmaceutical spending. The proliferation of high-cost specialty medicines will be a major driver of health spending growth in the coming years. While some of these medicines bring great benefits to patients, others provide only marginal improvements. This challenges the efficiency of pharmaceutical spending.