The UK Medicines and Healthcare Products Regulatory Agency has directed Marketing Authorisation Holders (MAHs) for medicines containing specified controlled drugs to update their Summary of Product Characteristics, patient information leaflets, and product labeling. These new warnings are designed to make it easier for the government to enforce a new law prohibiting driving under the influence of drugs, to take effect later this year. For more information, read the full alert written by Reed Smith lawyers John Wilkinson, Nicola Maguire and Adam Lewington.