Even when opioids are appropriately prescribed, some patients may end up abusing or misusing them. In this review, studies on opioid abuse, misuse, or medication errors were analyzed. The most frequently mentioned opioids were morphine, fentanyl, and oxycodone. Adverse events occurred across the medication process including prescribing, dispensing, and administration. Rates of abuse and misuse varied across countries, typically due to drug availability.