In this episode I’ll:
1. Discuss an article about using platelet infusions to treat intracerebral hemorrhage (ICH) from antiplatelet medications.
2. Answer the drug information question “Why were the contraindications to alteplase for acute ischemic stroke changed?”
3. Share a resource I used to learn how to recognize ECG rhythms.
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Article
Lead author: M Irem Baharoglu
Published in the journal Lancet May 2016 via online first access
Background
A 2013 article concluded that giving platelet transfusions to patients on antiplatelet medications who experience ICH did not improve outcomes.
Nevertheless, platelet transfusion has still been frequently used for treating ICH in patients on antiplatelet medications. The authors of this article sought to investigate whether platelet transfusion plus standard care, compared to standard care alone, reduced death or dependence after intracerebral hemorrhage associated with antiplatelet medication use.
Methods
The trial was a multicenter, open-label, masked-endpoint, randomized investigation at 60 hospitals in the Netherlands, UK, and France.
The collaborators enrolled adults within 6 hours of supratentorial intracerebral hemorrhage symptom onset if they had used antiplatelet therapy for at least 7 days beforehand and had a Glasgow Coma Scale score of at least 8. The study collaborators randomly assigned participants (1:1; stratified by hospital and type of antiplatelet therapy) to receive either standard care or standard care with platelet transfusion within 90 minutes of diagnostic brain imaging.
Participants and local investigators giving interventions were not masked to treatment allocation, but allocation was concealed from outcome assessors and investigators analyzing data.
The primary outcome was death or dependence, rated on the modified Rankin Scale at 3 months.
Results
Between Feb 4, 2009, and Oct 8, 2015, 41 sites enrolled 190 participants. 97 participants were randomly assigned to platelet transfusion and 93 to standard care.
The odds of death or dependence at 3 months were higher in the platelet transfusion group than in the standard care group (adjusted common odds ratio 2.05, 95% CI 1.18–3.56; p=0.0114). 42% of participants who received platelet transfusion had a serious adverse event during their hospital stay, as did 29% who received standard care. 24% participants assigned to platelet transfusion and 17% assigned to standard care died during hospital stay.
Conclusion
The authors concluded that:
Platelet transfusion seems inferior to standard care for people taking antiplatelet therapy before intracerebral haemorrhage. Platelet transfusion cannot be recommended for this indication in clinical practice.
Discussion
The study had a relatively small sample size, and enrollment was very slow with sites averaging less than 1 enrollment per year. However the study is the best available evidence to answer the question of whether patients with ICH after antiplatelet medication use should receive platelet transfusions.
Drug information question
Q: Why were the contraindications to alteplase for acute ischemic stroke changed?
A: Lawyers.
Back in February 2015, the alteplase prescribing information (PI) underwent a radical change in the contraindication section. Many contraindications that were based on trial exclusion criteria and “common sense” were removed.
One would think that this change was based on some new evidence about the drug’s safety, but that is not the case. The change was made as part of a routine update to the PI to ensure that the information is consistent with the Physician Labeling Rule instituted in 2006.
The Physician Labeling Rule provides a standardized format with the goal of providing clear and concise PI that is easier for healthcare professionals to access, read, and use.
The Physician Labeling Rule definitions of contraindications and warnings and precautions are as follows:
• Contraindications: A drug should be contraindicated only in those clinical situations for which the risk from use clearly outweighs any possible therapeutic benefit. Only known hazards, not theoretical possibilities, can be the basis for a contraindication.
• Warnings and precautions: The warnings and precautions section is intended to identify and describe a discrete set of adverse reactions and other potential safety hazards that are serious or are otherwise clinically significant because they have implications for prescribing decisions or for patient management. For an adverse event to be included in the section, there should be reasonable evidence of a causal association between the drug and the adverse event, but a causal relationship need not have been definitively established.
The AHA/ASA recognized that the change to the prescribing information was not made in the context of new scientific information, and they have published a document titled: Scientific Rationale for the Inclusion and Exclusion Criteria for Intravenous Alteplase in Acute Ischemic Stroke. The AHA/ASA feels that clinicians should use the science in that document, along with their stroke management guidelines for stroke treatment and management decisions.
Resource
The website SkillSTAT has a great online ECG simulator & training app. I mentioned in very briefly back in episode 10 when I discussed how the Pharmacist and the ECG should be friends.
The app is called “The Six Second ECG”. It can be used to quickly learn to identify 27 of the most common ECG rhythms. In “preparation mode” the app displays and thoroughly explains each ECG rhythm. The app also includes a “gamified” challenge mode where the user attempts to correctly identify 10 rhythms in the span of 60 seconds.
I primarily used this online app when I was learning ECG rhythm recognition.
If you like this post, check out my book – A Pharmacist’s Guide to Inpatient Medical Emergencies: How to respond to code blue, rapid response calls, and other medical emergencies.
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