Table 1

Prescribing errors and ADR documentation errors with examples

Prescribing errors by stage of drug use processExamples
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 selectionVerapamil oral 240 mg each morning prescribed for hypertension, without specifying that sustained release formulation was required
Supply and administration written instruction errors
NameMetoprolol oral 50 mg bd was prescribed; patient had received 50 mg of haloperidol as the nurse had misinterpreted the unclear drug name
DoseEnalapril 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 frequencyCeftriaxone 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 frequencyMissing 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.