Medication Errors

Medication safety is a top priority for nurses and avoiding medication errors is critical. Find out what medication errors have recently been reported to the Institute for Safe Medication Practices (ISMP) and learn recommendations for best practices to help avoid these errors.

Confusing Glucometer Results

Glucometers are devices used to perform point-of-care (POC) glucose testing in the hospital setting to monitor and manage high and low blood glucose levels. Errors related to the use of these devices may result from factors such as delays in testing due to lack of properly trained staff; failure to correctly identify patients prior to testing; and the effects of hematocrit, ascorbic acid levels, maltose-containing medications and parenteral solutions on glucose levels.

A serious error that has been reported is the misinterpretation of glucose results on glucometer devices that use error messages and alarm codes. Devices like the ACCU-CHECK Inform II may display results in several different ways including the use of out-of-range abbreviations such as RR LO (out of reportable range; low limit) or CR LO (out of critical range; low limit), numeric alarm codes (i.e. W-510) and low numerical results (i.e. < 40 mg/dL). Both RR LO and CR LO messages have been misunderstood as high blood glucose levels along with the numeric alarm code W-510 which was confused as the actual glucose result. Insulin was erroneously given to two patients with one resulting in a patient death.

One study conducted by the Veterans Health Administration (VHA) found that displaying a numeric blood glucose result instead of an abbreviation could prevent misinterpretation errors. Prior training on the glucometer devices may be helpful but will not completely remove the risk of errors when abbreviations are shown. The study also found that nurses can interpret numeric blood glucose readings faster than abbreviations which is optimal when treating patients with hypo- or hyperglycemia. While not studied, these results may be applicable to the abbreviations RR HI (out of reportable range; high limit) and CR HI (out of critical range, high limit).

The following strategies may help reduce confusing glucometer readings:
  • Accu-Check Inform II Glucometers:
    • Set the range to coincide with the entire measurement range of the device (10 mg/dL to 600 mg/dL) to prevent the display of RR LO or RR HI abbreviations.
    • Ensure the critical results display as a numeric value to prevent display of CR LO or CR HI abbreviations.
    • Provide education and simulation training on out-of-range abbreviations, unusual alarm codes, and alert wording that may appear on the glucometer screen along with their meaning, and risk of misinterpretation.
  • For other types of glucometers:
    • Assess the glucose results display and determine if it contains confusing wording, terminology, alarm codes, or abbreviations. If possible, configure the glucometer to display the actual numeric blood glucose value instead of out-of-range codes and alarm messages.
    • If the glucometer cannot be configured, contact the manufacturer for assistance or switch to a different manufacturer that produces a device that can be configured.
    • Educate staff on the alarm codes and warning messages if they must be displayed, particularly if they include numeric values.

Drug name stem “-oxacin”

The drug stem “-oxacin” specifies the antibacterial class of drugs known as fluoroquinolones which are used to prevent and treat bacterial infections by obstructing DNA creation in bacterial cells. Organisms that are susceptible to fluoroquinolones include gram negative pathogens such as Pseudomonas, gram positive, atypical bacteria and bacteria associated with community-acquired pneumonia. Fluoroquinolones come in several formulations including: intravenous (IV), oral solution, oral tablet, ophthalmic solution and ointment, otic solution, and intratympanic suspension. Oral formulations should be given a minimum of 2 hours before or 6 hours after antacids and drugs containing calcium, aluminum, magnesium, iron or zinc, all of which may decrease the absorption of “-oxacin” drugs if given simultaneously.

Side effects of systemic fluoroquinolone antibiotics include headache, dizziness, nausea, and diarrhea, including Clostridium difficile. Serious adverse effects that may occur are: peripheral neuropathy, tendon rupture, tendonitis, aggravation of myasthenia gravis, mental health side effects (i.e. agitation, memory impairment, delirium, nervousness), hypoglycemia that could lead to coma, and increased risk of aortic aneurysm or dissection that can lead to bleeding and/or death. Fluoroquinolones should be avoided in patients with a history of blood vessel or aorta blockages or aneurysms, high blood pressure, genetic disorders such as Marfan syndrome and Ehlers-Danlos syndrome, and the elderly. Monitor and educate patients on the signs of hypoglycemia as well as the risk of psychiatric side effects after only one dose.

Fluoroquinolones and combination drugs currently available on the market include:
  • Ciprofloxacin – Cipro, Cipro in D5W, Cipro XR, Ciloxan, Cetraxal, Otiprio
  • Ciprofloxacin/dexamethasone – Ciprodex
  • Ciprofloxacin/fluocinolone – Otovel
  • Ciprofloxacin/hydrocortisone – Cipro HC
  • Delafloxacin – Baxdela
  • Gatifloxacin – Zymaxid
  • Levofloxacin (generic only)
  • Moxifloxacin – Avelox, Moxeza, Vigamox
  • Ofloxacin – Ocuflox, Floxin Otic

Safety Issues

Confusing “thousand” and “million” abbreviations
Some drug wholesalers use different abbreviations for medication strengths such as AmerisourceBergen’s labeling for Retacrit, Epogen and Procrit. The Procrit vial contains 20,000 units which is listed as “20K UN/ML”, while the Retacrit vials contain 10,000 units and is listed as “10M UN/ML” which can cause confusion. The letter M is often used to denote millions and the letter K (kilo) is commonly used for thousand. However, M is also the Roman numeral for 1,000 and is used by some companies for this abbreviation. The letters MM have also been used to abbreviate million (1,000 x 1,000). To decrease confusion in hospitals, large doses should be displayed using words (million and thousand) instead of abbreviations. Using numbers may be prone to errors as a dropped zero or misplaced comma can lead to administration of the wrong dose. If numbers must be used, ensure commas are correctly placed and zeros are not accidentally dropped.

Phenylephrine Dosing Error
503B compounding pharmacies are external pharmacies that prepare batches of medications for hospitals to purchase. Clinical staff should be aware of the use of 503 pharmacies and their products. A patient was ordered 100 mcg of phenylephrine for acute hypotension. A nurse pulled a 503B out-sourced prefilled phenylephrine syringe which was packaged in a 10 mL syringe labeled phenylephrine HCl 100 mcg/mL (1 mg/10 mL). The labeling used is opposite of commercial labels, which typically lists total dose and volume followed by per mL concentration. The nurse administered the entire volume of the syringe, 10 mL or 1,000 mcg , 10 times the prescribed dose. The patient’s blood pressure increased but returned to normal limits within 10 minutes. The US Food and Drug Administration (FDA) requires that labels should list the total amount of drug per total volume (i.e. 1000 mcg/10 mL) in the container followed by the strength per mL (i.e. 100 mcg/mL). However, 503B outsourcers are not required to follow FDA labeling requirements which has resulted in drug errors and overdoses. Ensure staff are aware if 503B wholesale suppliers are used and to check the strength of the drug carefully to prevent drug errors.

Pen Needle  Mistakes
Standard pen needles are made with an outer cover and a removable inner needle cover, both of which need to be removed before injection. Safety pen needles have an outer cover that is removed, and an inner needle cover that is not removed prior to injection. Hospitals typically use safety pen needles to prevent needlesticks. Staff may teach patients how to use self-injection pens such as insulin and epinephrine using the safety needle. However, if patients later purchase a standard pen needle, they may not be aware that the inner cover needs to be removed. If it is not removed, the needle will not penetrate the skin and the patient will not receive the drug. Ensure staff instruct patients on the different types of pen needles and which ones require the removal of an outer and inner needle cover.


  1. Institute for Safe Medication Practices. (2019). Nurse Advise-ERR. Retrieved from Institute for Safe Medication Practices: 

More Nursing News Headlines (Pharmacy)...

Powered by