Are More Patients Eligible for Alteplase?

Back in April 2015, I wrote about the updated prescribing information for alteplase and the changes to the

tissue plasminogen activator

's contraindications. In a nutshell, the prescribing information was updated to reflect the formatting standards set forth in the 2006 Physician Labeling Rule.

In this new formatting, the drug is contraindicated only in clinical situations where the risk related to use clearly outweighs any possible therapeutic benefit. This excludes theoretical possibilities and accounts for only known hazards.

At this time, the guidelines for the management of acute ischemic stroke remain unchanged, so although a seizure at the onset of stroke is no longer a contraindication based on alteplase’s prescribing information, it is still an exclusion based on the clinical guidelines.

Now, a new joint scientific statement issued by the American Heart Association and the American Stroke Association appears to be formulating the building blocks to amend the guidelines. This scientific statement is essential reading material for any pharmacist involved with the acute management of ischemic stroke.

The writing group analyzed the evidence behind each amended contraindication and provided a summary recommendation on whether or not the evidence supports the contraindication moniker. Specific items addressed ranged from recommendations on age, to stroke severity, to diabetic hemorrhagic retinopathy, to other ophthalmological concerns.

The scientific statement also clarified certain concerns regarding elimination of contraindications such as history of intracranial hemorrhage.

Although it is no longer a contraindication in the drug’s prescribing information, the authors pointed out that administrating alteplase to patients with a history of intracranial hemorrhage is harmful. However, they specified that alteplase may be reasonable in certain patients with cerebral microbleeds (Class IIa, Level of Evidence B).

Furthermore, there was speculation regarding the ability to initiate alteplase prior to controlling a patient’s blood pressure if it was greater than 180 mm Hg systolic or 110 mm Hg diastolic, given that it was no longer a contraindication in the prescribing information. However, the scientific statement authors clarified that it is not reasonable to begin alteplase until hypertension is controlled beneath these figures.

How this scientific statement will impact clinical practice remains unclear. The authors stated that these recommendations are not intended to replace the guidelines, but rather serve as an adjunct.

Clearly, if these statements were intended to change guidelines, they would have been reflected in a guideline update. Nevertheless, the associations may have chosen this format to gauge their impression on stroke care providers at the International Stroke Conference in February.

Reference

Demaerschalk BM, et al. Scientific rationale for the inclusion and exclusion criteria for intravenous alteplase in acute ischemic stroke: a statement for healthcare professionals from the American Heart Association/American Stroke Association. Stroke. 2016;47 [Epub-ahead of print]