Dear Editor:

I am surprised to see the continued use of the term tissue plasminogen activator and its abbreviation "tPA" by the Journal of Neuroscience Nursing when referring to alteplase (or Activase). This most recently occurred in the February 2018 issue.1

Ten years after publishing the article "Thrombolytic Alphabet Soup: A Recipe for Disaster," the Institute for Safe Medication Practices recommended that the abbreviation "t-PA" or "TPA" for tissue plasminogen activator not be used when referring to alteplase, including verbal or written orders.2-5 This recommendation extends to the abbreviation "TNK" when referring to tenecteplase (TNKase). In September 2015, the US Food and Drug Administration (FDA) further recommended that these abbreviations not be used when publishing medical literature or clinical guidelines and that hospitals remove these abbreviations from all standardized order sets and treatment protocols.5 In addition, The Joint Commission, as part of their national Patient Safety Goal program, requires hospitals to limit their use of abbreviations.6 Although "tPA" and "TNK" are not officially listed on their "Do Not Use List," The Joint Commission expects healthcare organizations to maintain a standardized list of "do not use" abbreviations, acronyms, and symbols.6

Currently, there are 3 FDA-approved recombinant tissue plasminogen medications: activase (Activase), tenecteplase (TNKase or "TNK"), and reteplase (Retavase). Indications for use include acute ischemic stroke (AIS), myocardial infarction, deep vein thrombosis, acute arterial occlusion, pulmonary embolus, and cannula/catheter occlusion, although not all medications are approved for all conditions and dosing differs based on agent and indication. Originally approved for acute myocardial infarction in 1987, alteplase is the only agent from this list currently approved by the FDA for use in neuroscience. Alteplase was approved in 1996 for AIS when given within 3 hours of symptom onset. National guidelines published in 2009 extended the treatment window from 3 to 4.5 hours in a further subgroup of patients.7

Institute for Safe Medication Practices recommendations are based, at least in part, on medical errors reported to the Institute for Safe Medication Practices and the FDA involving the abbreviations "tPA" and "TNK." Between 2000 and June 2014, the FDA alone received 21 cases of wrong drug administration errors associated with tenecteplase.5 This included at least 7 cases where patients with AIS were inadvertently given tenecteplase in place of alteplase. These errors were directly "attributed to confusion between the two abbreviations."5 The earliest publicly reported errors of this type are outlined in a letter to the journal Stroke in 2001.8

Although the abbreviations "tPA," "TPA," or rt-PA" are often used when referring to alteplase, they are also used when referencing the larger class of recombinant tissue plasminogen activator medications. Both "tPA" and "TPA" are also used to denote the tissue plasminogen activator protein, the major enzyme responsible for catalyzing the conversion of plasminogen to plasmin (the targeted action of these recombinant medications). Unlike many medication errors involving similar names or abbreviations, alteplase and tenecteplase have similar pharmaceutical properties. Because the dose for alteplase is most often higher than the maximum tenecteplase dose (0.9 mg/kg with a maximum dose of 90 mg vs 0.4 mg/kg in AIS), a tenecteplase overdose may easily occur if inadvertently administered based on alteplase dosing (as reported by the FDA and by Smith and Davis).5,8 A tenecteplase overdose increases the risk of intracranial hemorrhage, retroperitoneal bleeding, prolonged hospitalization, and death.

Besides increasing treatment rates with alteplase for AIS, both alteplase and tenecteplase are being evaluated for new indications. Although not FDA approved, alteplase is being administered intrathecally in patients with cerebral hemorrhage with extension into the ventricles to help maintain patency of external ventricular catheters and to facilitate intraventricular hematoma removal.9,10 Tenecteplase is being evaluated for use in AIS in completed and ongoing trials and as an adjunct to endovascular therapy.11,12

In conclusion, preventing adverse medication errors is a priority for the US health system. With the known risks associated with these medications and their expanding use, it is imperative that healthcare providers establish and maintain safe medication practices when referring to and administering these potent but often life-changing medications. As a leading authority in neuroscience nursing, the Journal of Neuroscience Nursing has an obligation to lead the way by adopting recommended guidelines to abandon the use of these dangerous abbreviations to help promote safe patient care.

References