Pharmacovigilance is about making drug products, as well as their use, safer. While the set-up for ADR monitoring catches product problems, it may also be a good system to detect if such a product was not being properly used. Medication error is one such problem. Lessons from medication error detection may help prevent future errors and protect health professionals and ultimately, their patients.
Generally, there is difficulty in obtaining the correct statistics on medication errors. Many of these errors are neither recognized nor reported. A study was published in the Archives of Internal Medicine based on data collected since 1999. In the United States, more than 40 potentially harmful errors a day were found on average in hospitals. The most common mistake is giving medicines at the wrong time, completely omitting the dosage, and over-dosing. Errors occurred in one of five doses in a typical 300-bed hospital. This translates to an average of 2 errors per patient daily. Although not all of these errors are dangerous, 7% of the errors were considered potentially harmful.
Medication errors can lead to manslaughter charges. The topic of medication error will make pharmacovigilance instruction more relevant and interesting. It will help prevent malpractice litigation and promote public health safety and awareness. While it is the drug regulator’s role to help improve the quality of drug and drug use by providing standards, medication errors can be minimized, if not completely eradicated at the clinical side. Its occurrence reflects on the quality of health care.
Causes of Medication Errors and some examples:
Errors originating from the drug industry:
1. Mistakes can happen in the manufacture of medicines (e.g. using the wrong excepients)
2. Proper storage procedures are not observed, making the drugs useless. Using expired tetracycline has been known to cause Fanconi’s syndrome, for instance.
3. Failure to provide the correct prescribing information. For example 10 mg/kg 6 hourly could mean: 10 mg/kg per dose given every 6 hours, which is the wrong interpretation, or 10 mg/kg/day to be divided every 6 hours which is correct.
4. Failure to do Post-Marketing Surveillance by manufacturers. And, if done, not communicating these data.
5. Misleading health and treatment claims by the industry.
Errors arising from medical doctors’ prescriptions
1. Prescribing the wrong drug
2. Writing illegibly
3. Confusing the name of one drug with that of another
4. Prescribing the wrong dose
5. Writing wrong dose
6. Wrong route of administration as listed in the prescription
7. Prescribing the wrong formulation (an example is using slow release drugs inadvertently when the doctor meant ordinary tablets)
8. Prescribing the duration of treatment incorrectly
9. Prescribing wrongly for a given individual
10. Error in identity of the patient.
11. Failing to account for pre-existing disease
12. Failing to account for concurrent therapy
13. Prescribing with inadequate or incorrect instructions
14. Prescribing without informed consent of the patient
15. Off-label use of drugs
Errors arising from pharmacists’ dispensing
1. Dispensing errors – for example, giving 250 mg/5mL paracetamol instead of the prescribed 125 mg/5 mL preparation.
2. Misinterpreting doctor’s prescription and failure to confirm with the prescriber.
3. Failure to provide advice to patients at the outlet level. In poor resource countries, patients sometime purchase only a few tablets because they cannot afford a complete course of treatment. The pharmacist or store clerk sells the medicines by cutting the medicine strips. As a result, the expiry dates are sometimes no longer indicated on the purchased portion and product information leaflets are rarely provided in such instances.
Errors arising from nurses’ administration of drugs
1. Errors in drawing up and giving medicines
2. Wrong drug
3. Correct drug, wrong dose
4. Correct drug, wrong dilution
5. Correct drug, wrong formulation
6. Entraining air, particles or other contaminants with the drug
7. Errors in administration (interchanging IV, IM, intrathecal, oral, sublingual route)
8. Giving a drug outside or against currently accepted practice (off-label usage)
9. Wrong route, wrong site, wrong rate, wrong patient
Errors arising from patient’s drug intake:
1. Misunderstanding medication instructions.
2. Poor patient compliance, not completing dosage regimen.
3. Drug paroxysm. This is when a patient takes a medicine but later becomes confused whether he actually took the medicines and ends up taking a second dose erroneously. This is not restricted to geriatric patients.
To counteract these possible errors, good prescribing practice guidelines are advocated:
• If it is possible to write the dose as a whole number, then do so.
• If it is impossible or more confusing to write the dose as a whole number, then ensure that a zero precedes the decimal point. Place the decimal point properly; a shift can mean 10 times more the intended dose, or can mean receiving only 10 percent of the intended dose. Use Gm for gram and gr for grain when specifying quantity. The best is to carefully spell out the whole word and dot the i. If grams are given instead of grains, the patient will receive approximately 15 times the dose intended.
• Communicate clearly. New technology like mobile phones and short message sending (texting) can lead to errors. Hospital should set up clear policies on telephone orders to prevent mistakes. Among the doctors, nurses and pharmacists, when transmitting orders, clear pronunciation of medical terms and listening carefully can preventmistakes of similar sounding drug names.
• Write a prescription clearly and give the instructions to patients or their responsible companions. There was a case of an obese diabetic patient who was being managed with oral hypoglycemic medicine and instructed to decrease weight in a vague manner. The patient decided to skip breakfast as a “diet control” measure but continued taking her medicine, leading to symptomatic hypoglycemia.
• Prescription should have all the essential information like dosage strength, the number of tablets, frequency of administration, route.
• Be conservative. Prescribe only when absolutely needed. Don’t satisfy the whims of patients who request antibiotics to treat common colds.
• Know your patient’s conditions well before prescribing any drugs.
• Prescribe a medicine which you are thoroughly familiar with (adverse effects, contraindications, warnings). Do not be tempted to prescribe new medicines which are being promoted aggressively by drug companies.
• If you want to prescribe a generic drug, it is better to indicate the particular company source you trust, for two reasons: substitution of another company’s generic product can mean lower drug levels (for drugs with serious bio-availability variations) and, in some countries, there are substandard generic products in the market.
• Avoid overprescribing because this is costly and can lead to accidental overdose. Sometimes, an expired drug is unintentionally taken. Also, warn patients not to recommend an effective drug which they may have in excess at home to a member of the household or a neighbor without consulting a health professional.
• Avoid polypharmacy. Although not all polypharmacy is bad when these medicines are actually needed, be attentive to those with potential for harmful interactions. Be wary of drug-drug interactions.
• Spend time to educate a patient about the drug-- when to take it, when to stop, what to expect (e.g., will it change the color of their urine?), how to recognize drug reactions and what to do, expiration dates, drug interactions and storage conditions. Patients should be made to understand that when they take medicines, they are essentially betting that the benefits derived from using the drug outweigh the harmful risks from the medicine and the consequence of the untreated disease condition. There are some medicines which, when started, should be continued for a long time (e.g. Anti-TB drugs and prevention of resistance).
• There are some drugs which, when taken for a long time, should not be stopped abruptly (e.g. Anticonvulsants, steroids, sedative hypnotics)
• There are also some drugs which, when taken long term, may lead to drug dependence and abuse.
• Pay serious attention to the patient’s history, such as records of hypersensitivity, allergies, idiosyncracies to medicines, or medical conditions that are considered contraindications to drugs. Note these in patient’s records and review them when necessary before prescribing. Take note of the patient’s occupation and possible risky interactions with his medicines.
Drug safety and rational drug use
Due care must be exercised when handling drugs and treating patients. Negligence may lead to fatality, and commonly, a health professional may be charged with acts or omissions such as:
a. Not using available, objective and updated drug information and relying solely on drug industry detail person for this information.
b. Miscommunications on drug orders like poor penmanship, confusion between drug names, misuse of zeros and decimal points, wrong dosing units, and incorrect abbreviations.
c. failure to obtain consent from a patient for the use of a drug in a manner not officially approved (off-label)
d. treatment of a condition with a drug not suitable for the condition
e. failure to note a history of drug hypersensitivity, concurrent medications, contraindicated medical conditions.
f. failure to test patient for sensitivity to drugs like penicillin
g. improper injection techniques
h. failure to stop a medicine suspected to cause a reaction
i. failure to provide adequate intervention to counteract an adverse reaction
j. failure to communicate with patients.
k. lack of correct labeling when drugs are repacked into smaller units
It is by recognizing possible errors that we can find suitable ways to prevent them.
Some practical tips.
Dangerous abbreviations that can occur in the pharmaceutical laboratory, pharmacies, hospital and clinical practice are presented here.
• D/C - as used in the hospitals can mean discharge, discontinue or dilatation and curettage
• AU vs OU – because of spelling errors, can confuse both ears with both eyes.
• DPT vs dPT - A cocktail drug preparations used in hospitals known as Demerol, phenergan and thorazine can be confused with pediatric vaccines called diphtheria, pertussis, and tetanus.
• HCl vs KCl – again, H and K can be misread and instead of hydrochloric acid, potassium chloride is used.
• MgSO4 vs morphine – Morphine sulfate might erroneously be substituted for Magnesium sulfate used in obstetrics for pre-eclampsia and eclampsia
• OD vs right eye – Once a day and the right eye can be confusing.
• Per os vs left eye – os is sometimes used in hospital charts to mean opening, by mouth or by tube and can also mean the left eye.
• QD vs QID – once a day may be confused with four times a day.
• QN vs every hour qh – as letter N and H can be misread, every night is mistaken as every hour.
• QOD vs daily – this is particularly confusing when doctors make abbreviations misinterpreting every other day, or once every day.
• Sub q (subcutaneous) misread as every so hours.
• SC vs SL - because of possible pensmanship error, C for cutaneous can be mistaken as L for sublingual.
• IU vs IV – international units as opposed to intravenous, for instance, insulin expressed in units to be given subcutaneously may be erroneously given as intravenous bolus.
• X3d vs three doses – the confusion here may be due to misinterpretation that a drug is given for 3 days as opposed to just three doses or three times in a day.
• Inderal40 vs Inderal 40 mg (mistaken 140 mg) - it is not unusual to have a wide range of dosing for propranolol therapy as in the management of hyperthyroid states but when there is a penmanship mistake-- in this case, the absence of a space between the last letter and the subsequent number-- a mistake can happen.
Use of Cellphones for medical activities:
2 TXT D DOC or NOT 2 TXT?®
Mobile phones have replaced pagers as the preferred communication tool of doctors. More and more medical doctors are using mobile phones to convey orders to nurses in the hospitals. Some are using the short messaging system (SMS) feature of mobile phones (i.e. test messaging) to transmit sensitive instructions. Nurses in hospitals nowadays are beginning to use the same to inform doctors of admissions and status of patients’ conditions. There are potential problems, however, such as errors in text message content, delay in receiving information and hence delayed response. Lives may be at stake. Sometimes senders do not identify themselves and what institutions they come from. Sometimes the senders do not get the benefit of a reply. There is also a problem with text- style writing- i.e., abbreviated words, incorrect grammar that might lead to gross misunderstanding of the messages. Who might be liable in case of errors or failed response?
The SMS feature of mobile phones could potentially be an efficient tool for health professionals- particularly doctors and nurses. Currently, however, protocols are non-existent. As a response to the absence of protocols with respect to the use of text messaging, The Zuellig Foundation, in consultation with health professionals from various hospitals within Metro Manila, is suggesting the following guidelines for the best use of this new technology in saving lives.
1. Given the emerging importance of new telecommunication technology in the country, hospitals and other health facilities should always be ready to adopt and regulate this to their advantage by developing sound policies as it applies in their own setting.
2. Given its various limitations, the use of text messaging in giving orders to nurses should be limited in extreme cases where the use of other means in relaying the message (e.g. telephone calls) are absent there is an urgency for doctors to do so. Remember that the patient’s lives are at stake in these situations and there is a need to relay messages as fast and as accurately as possible. At any rate, in an emergency, it might be better just to call the hospital using phone rather than rely on text messaging.
3. Most hospitals have standing operational definition of what urgent cases are. If this standard definition does not exist, the hospitals’ administration should develop one and apply it to limit and appropriately regulate the use of text messaging to relay doctors’ orders to nurses.
4. Hospitals and other health facilities should also consider investing in new telecommunication technology that can facilitate documentation/verification of doctors’ orders via text messaging (e.g., a machine that can print \out text messages, telephone equipped with long distance call features, mobile phones and other applicable telecom equipment).
5. If there’s a need to use text messaging in giving orders, doctors should always consider sending it first to a fellow physician (e.g. residents or fellow consultants) who can then personally write/make the order himself. This can remedy the issue of legal liability or professional accountability for both nurses and the physician.
6. Doctors should never forget to include their name in the text message or if possible, a PIN or other forms of identification that nurses and other hospitals staff can officially recognize.
7. Doctors using text messaging in conveying their orders to nurses should be able to at least wait for one to two minutes for the nurses to acknowledge them or they must at least provide sufficient time for response; remember that one may not be able to return text messages or call immediately.
8. Nurses, on the other hand, should acknowledge doctors’ orders as soon as possible by forwarding the original message and together with their name or identification and other relevant or appropriate responses.
9. Nurses should take note of the exact time when the message was sent by the doctor and the time they were able to respond. They should make sure that the doctors making the orders should be able to respond back to them within one or two minutes.
10. Doctors and nurses exchanging messages through text should be familiar and limit themselves with conventional abbreviations of drugs/medications’ preparations and dose/dosage, among others. The use of uncommonly used or new abbreviations might be interpreted inaccurately and might have serious consequences in patient care.
11. Doctors should make it a point to personally acknowledge their orders by countersigning them later on in the patient’s chart. Hospital administration should decide the time frame within which doctors should accomplish this.
12. Given the many limitations of text messaging in relaying vital information, a telephone call must always be considered as better alternative. However, hospital administration should also consider developing written policies as they apply for this purpose.
Medication errors can happen unintentionally. Any health professional should be vigilant in finding ways to prevent and mitigate these errors. One way is to strengthen education and surveillance systems within the ADR reporting context. The role of pharmacovigilance centers or ADR National Centers can be expanded to address problems that occur in the clinical setting. Every health professional involved in the therapeutic chain should always question the decisions made by the ones before them (nurses and pharmacists question the prescriber on medications as prescribed etc.).
It would be serious to hear this from our patients: “Doctor, I prefer the disease to the side effects of the medicines you gave.”
Barker, KN, et al (2002) Medication errors observed in 36 health care facilities.
Archives of Internal Medicine.162: 1897-1903.
Bedell S et al. (2000). Discrepancies in the Use of Medicines. Archives of Internal Medicine, Vol. 160: 2129-2134
Ferner RE. (2000) Medication errors that have led to manslaughter charges. BMJ 321:1212-1216.
Ferner RE & Aronson JK. (1999). Errors in prescribing, preparing, and giving medicines: definition, classification, and prevention. In Side Effects of Drugs Annual 22. Elsevier Publishing.
Ferner RE. (1996). Forensic Pharmacology: Medicines, Mayhem and Malpractice. Oxford University Press
Zuellig Foundation’s think tank policy notes on the use of cellphone (text messaging or SMS) in hospitals 2002.®