Prescribing errors and ADR documentation errors with examples
| Prescribing errors by stage of drug use process | Examples |
| Drug dose and form prescribing decision errors | |
| Need for drug treatment (duplication) | Patient already prescribed Tritace (ramipril) 10 mg each morning, had lisinopril added |
| Specific drug selection (re-expose patient to drug which caused previous ADR) | Patient allergic to penicillin (hives, rash) started on dicloxacillin |
| Drug dose selection (wrong dose or frequency) | Prescribed enoxaparin 70 mg twice a day, patients weight 55 kg should have been 1 mg/kg (ie, 50 mg) twice a day |
| Drug formulation selection | Verapamil oral 240 mg each morning prescribed for hypertension, without specifying that sustained release formulation was required |
| Supply and administration written instruction errors | |
| Name | Metoprolol oral 50 mg bd was prescribed; patient had received 50 mg of haloperidol as the nurse had misinterpreted the unclear drug name |
| Dose | Enalapril oral one tablet each morning prescribed without specifying the strength. |
| Unacceptable ambiguous dosing instructions included no leading or unnecessary trailing zeros (.1 g or 5.0 mg), U (for units), ug for mcg or micrograms. | |
| Regular frequency | Ceftriaxone IV 1G od prescribed, the od looked like qd and a nurse had entered administration times of 06:00, 12:00, 18:00 and 22:00 instead of 08:00 only |
| Unacceptable ambiguous regular frequency instructions included od, which could be interpreted as once, twice or four times each day. 6h, 6/24 or 6°—all of which are used for 6 hourly but can be misinterpreted. | |
| PRN frequency | Missing PRN frequencies: morphine intravenous or intramuscular 2.5–5.0 mg PRN. There was no indication of minimum time interval between doses or maximum dose over time. |
| Unclear PRN frequencies: for drugs that could be administered more than once a day. Tds doses could be interpreted as three doses in 24 hours or every 8 hours. Multiple dose per 24-hour period instructions were required to be documented hourly. |
ADR, adverse drug reaction; PRN, pro re nata, or as required.