The new study tallies some of the costs of overdoses. About 41% of the patients who went to a hospital after taking prescription opioids were treated in the emergency room and released; 55% were admitted to the hospital. And 4% were transferred to an acute care hospital. Among those who became hospital inpatients, the average stay was 3.8 days, and their average charges came to $29,497. For patients who were released without being admitted, the average charges were $3,640. Altogether, the cost of treating both groups of patients was nearly $1.4 billion in 2010.