| Medication discrepancy | | |
| Discontinuation | Discontinuing a patient's regular medication without explanation | Patient is taking 20 mg of citalopram at home, but this is discontinued on admission to hospital |
| Omission | Patient's regular medication is not listed on medication reconciliation form and is not reordered | Patient is taking 81 mg of acetylsalicylic acid (over the counter) daily, but this is not listed on medication reconciliation form. It is not ordered during hospital stay. |
| Change in dosage | Medication is ordered at dosage indicated on medication reconciliation form, but patient is taking different dosage | Patient was prescribed 25 mg of metoprolol twice daily, but family doctor had decreased dosage to 12.5 mg by mouth twice daily. Patient receives 25 mg twice daily in hospital without indication for increased dosage. |
| Change in route | Medication is ordered via route indicated on medication reconciliation form, but patient is taking it differently at home | Patient was prescribed acetaminophen, 1000 mg by mouth 3 times daily per rectum, in nursing facility because of decreased level of consciousness. It is ordered by mouth in hospital. |
| Change in frequency | Medication is ordered at frequency indicated on medication reconciliation form, which differs from patient's regimen | Patient was prescribed gabapentin, 300 mg 3 times daily, but is taking it only at bedtime because of daytime somnolence. Medication is ordered as 300 mg 3 times daily in hospital. |
| As needed to regular | Medication is ordered regularly as per medication reconciliation form, but patient is taking it as needed | Patient was prescribed zopliclone, 7.5 mg at bedtime, but is using it as needed, and only infrequently. It is ordered regularly in hospital. |
| Regular to as needed | Medication is ordered as needed as per medication reconciliation form, but the patient is taking it regularly | Patient was prescribed lorazepam, 0.5-1 mg 3 times daily as needed, but is taking 1 mg 3 times daily regularly. It is ordered as needed in hospital. |
| Error of commission | | |
| Reorder error | Reordering a medication that had previously been stopped | Patient was prescribed indomethacin for acute gout flare-up but had stopped it when flare-up subsided. It is erroneously reordered in hospital. |
| Inappropriate continuation | Ordering a medication that patient is taking in the setting of a new contraindication | Patient is taking indomethacin for acute gout flare-up and then presents with gastrointestinal bleed. Indomethacin is inappropriately continued in hospital. |