Study On Medication Errors- Causes And Prevention

Medication errors are defined as any mistake or false judgment in prescription, dispensing or administering medication, thus it may be a doctor’s, a pharmacist’s or a nurse’s mistake.

In USA the Institute of medicine reported that 44,000 to 98,000 deaths caused by medical errors yearly.7,000 of them due to medication errors. In addition, Johnson and Bootman calculated 116 million visits to doctors, 17 million visit to Emergency Department, 8 million hospital admissions and 3 million long-term care admission per year due to medication errors (Kwabena 2004).

We are going to discuss the most common types of errors, the causes of errors and some of the strategies to reduce and prevent medication errors.

Types of Medication Errors

Three people involve in medicine, the doctor who will order the medicine, the pharmacist who will supply the medicine and the nurse who will give the medicine. Any mistakes done by any one of these three people will result in medication error. Thus, there are three main types of medication errors, the prescribing errors, the dispensing errors and the administering errors.

Prescribing errors:

The doctors are responsible for prescribing the medicines for the patients. There are three types of prescribing error: using wrong drug name, wrong dose and wrong dosage frequency.

To start with, it is very common to use wrong drug name as there are new medicines entering the market every year. There are more than 17,000 trade and generic name for pharmaceuticals marketed in North America (Kwabena, 2004).In addition, the medicine dose and frequency vary from patent to patent for example, children, elderly and renal patents requires special attention in writing the dose. Furthermore, some medicines require special dose tapering before they can be completely stopped. Moreover, calculating the dose need special mathematical technique where doctors may not have the time and experience to do.

In interviews done in Australia with 15 doctors who had contributed to a significant medication errors, they admitted that the prescribing errors was due to slips in attention or lapses due to memory failures and 8 errors was knowledge- based mistakes. These mistakes happen when the doctors are busy, tired or working with unfamiliar patients or patients who have complex condition. The Knowledge-based mistakes were mainly due to the difficulty to access the drug information, guidelines or protocols. In some cases, junior doctors didn’t ask help as they don’t want to disturb a busy colleague or they were having low expectation to get help. This indicates serious communication problems in the team. In addition, two doctors state that they increase sedation for older patients because they felt pressured by nurses to do that. Furthermore, 10 of the 15 doctors did not know that, they caused a medication error until the research team approached then as the errors happened with unfamiliar patients (Nichols P, 2008).

Dispensing Errors:

Dispensing medicine is the pharmacist responsibility. Pharmacists are also responsible for integrating and evaluating the dose, the route, the frequency and the treatment duration.

In addition, the pharmacist should play a major role in answering all the medications enquires by the doctors and the nurses.

In UK and USA studies showed 10% incidence due to dispensing errors even in advanced medication distribution systems. In a study done in a public paediatric hospital in Brazil in 2005-2006, a total rate of more than 10% dispensing errors was found. Errors were classified as content errors, labelling errors and documentation errors (Costa LA, 2008).

The most common content errors were the “missing doses” where medicine was supply in smaller quantity than what was prescribed by the doctor. On the other hand the “other labelling errors” which include the illegible name or number were the most common labelling errors. The documentation errors represent only 1.7% of the total errors, 40% of these errors were absent or incorrect documentation of controlled drugs (Costa LA, 2008).

Another study showed that the dispensing errors were due to attention slips, memory lapses and knowledge-based errors. Like the doctors and the nurses, the pharmacist give reasons of being stressed, tired and busy in doing multiple tasks in the same time (Nichols P, 2008).

Administering Errors:

Administering medications is a nurse’s responsibility, thus; administering errors are nurse’s mistakes. It is fundamental for a nurse to know the medication and all the aspect related to the medication such as, the action, side effects preparation and there inter action with other medicine.

A study was done in two elderly long stay wards in UK psychiatric hospital, by using direct observation, chart review and the incidents reports. A head pharmacist was observing the routine and the PRN (as required) medication administration at each daily routine medication round for over two weeks, than the pharmacist was checking the medication chart to asses if any error has been occurred during the administration time. Another pharmacist was checking the chart and recording the medication errors which were recorded in the chart. This pharmacist did not know the result of the errors recorded by the first pharmacist. After that the incident report was checked to record the medication errors which were reported

during that period. The data was analysed after the observational period. Administering errors were very common, occurring in one of four doses. The most common errors detected

in this study were crushing tablets or opening capsules without the prescriber permission, omission of the dose without a valid clinical reason, failing to sing the medication chart and giving wrong medicines quantity. Moreover, the observational study detected two and a half times the numbers of error than the review of the medication chart. Furthermore, none of the detected errors were reported in the incident reporting system (Haw, 2007).

Another study was done in a University hospital in Sao Paulo state, Brazil. In this study, the nurses supervisors were asked to write down all the enquiries which were asked to them by the nurses during the study period and their answers to clarify the doubt, than they were asked to write the sources of their information. By analysing the data collected in this study, it was found that; the most common questions were about the medication dilution (40.4%), 15.7% doubts were about administering technique and 11% doubts about the drug interaction. Moreover the nurse supervisors who are considered as expert and knowledgeable professionals give 35.5% incorrect or partially correct answers. These answers may have caused adverse reaction to the patient. Furthermore, the nurse supervisors’ sources of answers were from their own knowledge, literature and colleagues from other areas. Only 7.5% answers were obtained from pharmacists who suppose to be the first source of information, this may be either because of difficulty to reach them as they are far away from the clinical

practice or because the nurses did not consider them as the best source of information about medicine (da Silva DO,2007).

Patient role in identifying the errors:

Patients are the best observer of their care in the hospitals. Can the patients and their families identify the problems, the injuries or the errors affecting their care in the hospitals? A study was done in a medicine unit of Boston teaching hospital in USA to answer this question. 228 inpatients were interviewed during their hospitalization and than ten days after their discharge. 62 patients reported that they have incidents or near misses.47 of the incidents reported were medication related problems. Half of the incidents were not recorded in the medical record and none were reported in the incident reporting system (Weingart SN, 2005).

Strategies to reduce the medication errors:

Hospitals and staffs (doctors, pharmacist and nurses) are responsible for patient safety during prescribing, dispensing and administering medication.

Hospitals are responsible for providing safe working roles and environment. First of all hospitals should restructure their systems to improve the human recourses by increasing the number of employ and reducing the shortage of staffs. On the other hand the working hours should be reduced, the nurse to patient ratio should be improved and a 24hour clinical pharmacist should be present. Than hospitals should improve the human resources level by On the other hand, staffs have the major role in reducing the incident. Following are some steps to reduce the medication errors: providing continues training programs and promoting recycling. The hospitals should also provide a clear dilution protocol, up dated literature and a prescribing guideline. Another thing hospitals should do is providing an easy access to internet. Hospitals should also provide an electronic prescribing system to reduce the incidents occurring due to difficult handwriting and should consider using the unit dose dispensing system. Finally, the incidents reporting system should be improved in order to encourage staffs to report the incidents.

Use a personal formulary with the frequently used medicine and keep it up to date.

Use a digital appliance with internet service if it is possible.

Be familiar with the medication, their actions, side effects and inter action with other medication.

Keep yourself updated by attending courses and workshops.

Follow the five rights (right patient, right drug, right dose, right route and right time) and always check and double check before writing, supplying and giving the medicine.

Doctors and nurses should clearly state the patients full name and his number before writing or giving the medicine.

Doctors should write the purpose of the medicine in the medication chart (with maintaining patient confidentiality).

Doctors should prescribe medicine only when needed, they should not prescribe medicine only upon patient request.

Take the allergy history of the drugs from the patient or his family.

Take the history of any herbal therapy used by the patient and be aware of the most common herbal drug and their actions and side effects.

Repeat the verbal order and be aware of the “sound alike” drugs especially when using the phone.

Ask the pharmacist help whenever needed as they are the best source of information in medication.

Take prober history when dealing with unfamiliar patients.

Be organized and try not to involve in many tasks at the same time.

In case of any doubt take experts opinion before dealing with the medication.

When dealing with any new or unfamiliar medicine read about it first.

When dealing with chronic patient asked about all his medicine and if possible ask him to bring all the medicine with him.

Good communication between the health team should be maintain.

Take extra percussion when dealing with special population such as children, elderly and renal patient.

Involve the patient and his family in his care and explain to him the action and side effects of his medication.


Medication errors are one of the most serious aspects interfere the patient’s safety in the hospitals. By following the prevention Strategies, the doctors, the pharmacist and the nurses can provide safe medication administration to the patient. Hospitals on the other hand, are responsible for providing safe environment for the staffs to insure safe medication administration. Finally, the incident reporting system should be improved. It is possible that the fear or the lack of awareness prevents staffs from reporting the incidence. Educational program should provided to encourage the staffs to report the errors before the adverse reaction can occur.