Medication errors
Although, strictly speaking, medication errors should come under the heading of clinical management, they account for such a high level of complaints, claims and adverse incidents that they deserve separate mention. The three most common errors reported in a recent study11 are:
- Wrong dose (21.9%)
- Omitted medication (20.2%)
- Wrong medicine given (10.1%)
Underlying these are myriad causes, such as those listed below. Most of the errors can be avoided by simple checking procedures and clear, open communication.
- Badly transcribed instructions
- Illegible prescriptions
- Miscalculation of dosage
- Confusion between similar-sounding drug names or similar-looking packages
- Clicking on the wrong drug in a drop-down menu
- Prescribing contraindicated drugs
- Not checking for potential drug interactions
- Not reviewing repeat prescriptions
- Failure to follow up/monitor
- Failure to act on laboratory results.
Most of the errors can be avoided by simple checking procedures and clear, open communication
Box 11: Medical Council guidance
“You must ensure as far as possible that any treatment, medication or therapy prescribed for a patient is safe, evidence-based and in the patient’s best interests. You should be particularly careful when prescribing multiple medications in case the combination might cause side effects.
"You should also take particular care when prescribing for patients who may have an impaired ability to metabolise the medication prescribed. You should weigh up the potential benefits with the risks of drug adverse effects and interactions when deciding what to prescribe. This also applies to the exercise of the prescribing of generic drugs. A patient’s treatment regime should be reviewed periodically.”
Source: Medical Council, Guide to Professional Conduct and Ethics for Registered Medical Practitioners (2009)
When writing prescriptions
- Be sure that the treatment is indicated.
- Check that the intended drug is not contraindicated and that the patient does not have a history of adverse reactions to it. Ensure that it will not interact with the patient’s other medication and warn the patient about any potential interactions with over-the-counter remedies.
- If issuing a hand-written prescription, write legibly, taking special care if the drug name could easily be confused with another – use capital letters and give the generic rather than trade name.
- If you use a computer for your prescribing, be aware of the risk of selecting the wrong drug from a drop-down menu (eg, penicillamine instead of penicillin).
- Write clear and unambiguous instructions for dosage, frequency and route of administration.
- Note the prescription and any other relevant information (eg, warnings given to the patient) in the medical record.
- Ensure that the patient is aware of what is being prescribed, and why. Use patient information leaflets to augment your verbal instructions, and be particularly careful to warn patients about possible side-effects, adverse drug interactions (including herbal medicines), or potentially dangerous activities, such as driving while taking drugs that induce drowsiness.
Check that the intended drug is not contraindicated and that the patient does not have a history of adverse reactions to it
Checking procedures
- Be particularly careful when choosing the dose for a drug you are not familiar with.
- If a pharmacist or nurse questions a drug order or prescription, check it carefully – many problems are prevented by helpful interaction between colleagues.
- Always read the label on the bottle or vial before administering a drug or other substance, such as water for injection.
- Establish the identity of the patient and double-check the prescription before administering medication.
Communication
- If you are prescribing medication to be administered by other members of the healthcare team, issue clear and unambiguous instructions – answer fully any queries they may have.
- Make sure that your outpatients understand how to take the medication you prescribe, and that you warn them of any possible serious side-effects or effects that would make driving or operating machinery dangerous.
- Document the administration of drugs and infusions (name, time, dose) in the appropriate place in the medical records.
Check that the intended drug is not contraindicated and that the patient does not have a history of adverse reactions to it
Box 12: Mis-heard verbal prescription leads to patient’s death
A patient, in the course of treatment in an acute hospital, was given parenteral morphine. The patient was sensitive to the drug and developed respiratory depression. The patient’s doctor called in an order for an ampoule of naloxone to be administered. A dose was prepared from ward stock and given but there was no response. A repeat order for a second ampoule of naloxone was also given and again the patient showed no improvement.
The nurse then questioned the doctor; “How much of this Lanoxin do you want me to give?” Instead of NaLoxone, the nurse heard LaNoxin. The patient subsequently died.
Contributing to the error, the nurse had not repeated back the verbal order to the doctor, and the doctor had prescribed an ampoule of the drug rather than a metric weight dose. The nurse had accepted the incomplete order and administered an ampoule of LANOXIN® (digoxin) both times.
Source: Irish Medication Safety Network, Briefing Document on Sound Alike Look Alike Drugs (SALAD) 2010.
Box 13: SALADs (Sound Alike Look Alike Drugs)
Examples of sound-alike and look-alike drug pairs that have been involved in errors and near misses in Irish hospitals:
| Actimel® / Actonel® |
| Amiodarone / Amlodipine |
| Anexate® / Anectine® |
| Carbamazepine / Carbimazole |
| Casodex® / Codalax® |
| Dipyridamole / Disopyramide |
| Lanoxin® / Naloxone |
| Losec® / Lasix® |
| Nicorette® / Nitroderm® |
| Nimodipine / Nifedipine |
| Novomix® / Novorapid® |
| Omacor® / Omesar® |
| Oxynorm® / Oxycontin® |
| Senokot® / Seroxat® |
| Zestril® / Xatral® |
Advice for prescribers to minimise the risk of SALAD mix-ups
- Write the full drug name when prescribing – never abbreviate.
- Specify the exact dose on the prescription – never use ‘as directed’.
- Consider ‘tall man’ lettering eg, OxyCONTIN®, OxyNORM® on prescriptions or labels etc. to identify key differences in high-alert SALAD pair names.