Generic substitution: a potential risk factor for medication errors in hospitals

Efforts to restrain pharmaceutical costs in the Norwegian hospital sector have focused on putting pharmaceuticals out to tender with resultant frequent changes in medicine inventories. Due to the extent of physicians failing to prescribe from the hospital drug list, the nurses have to perform generic substitution on the wards. The objective of the present study is to investigate the hospital nurses' experiences with generic substitution and to explore their views on this strategy as a risk factor for medication errors.

Personal interviews with 100 nurses who were employed in a large Norwegian hospital were conducted using a semistructured questionnaire.

In all, 75% of nurses thought it was problematic that the hospital's drug inventory was subject to frequent changes, and 91% believed that the high number of generic products may contribute to erroneous dispensing. Nevertheless, three out of four admitted that they seldom or never verified the feasibility of the substitution with the physician, and that it was seldom documented in the medical charts. In total, 42% of the nurses had experienced mistakes that occurred as a result of substitution. They claimed that the medication errors relating to generic substitution derived from difficult drug names, frequent changes in the drug inventory, and the increasing number of generic drugs, as well as from heavy workload and insufficient training.

The present study shows that generic substitution is often carried out by nurses on the wards. The nurses feel insecure about the situation and report that they do not have the necessary training for the task. They clearly believe that a high number of generic drugs and frequent generic substitutions are risk factors for medication errors. Hence, hospital managers should be aware that such strategies to reduce costs may interfere with patient safety.