Preventing Drug Diversion Act of 2018 This bill establishes a new requirement intended to help drug manufacturers and distributors identify and prevent suspicious orders of opioids and reduce rates of diversion. Specifically, the Drug Enforcement Administration must use its automated data system—the Automated Reports and Consolidated Ordering System—to inform drug manufacturers and distributors about the quantity and type of opioids that are distributed to pharmacies and practitioners. Additionally, the bill establishes new requirements for reporting, collecting, and sharing information about suspicious orders.