The permanent effects of stroke, a deadly brain injury characterized by reduced blood flow, can be limited by the timely administration of a drug called tissue plasminogen activator (tPA). tPA helps restore blood flow to the affected brain region. While administration of this drug is a common practice, not much is known about the effectiveness of different “loading dosages,” or boluses. It is a percentage of the total dose, typically 10% or 15%, that is administered to the patient within minutes. The rest of the drug is administered intravenously over the course of about one hour.
Drug dosages are often given as a proportion of someone’s body weight, such as milligrams per kilogram, or mg/kg. For tPA, the recommended administration is between 0.6 mg/kg and 0.9 mg/kg, which represent low and high doses, respectively. For example, a 75 kg person might be prescribed a dosage of 75 kg x (0.6 mg/kg) = 45 mg of tPA.
![drug vial](https://svgsilh.com/png/311107.png)
“plain” is licensed under CC0 1.0
Taiwanese neurologists were the first to compare outcomes in stroke patients who were treated with either 10% or 15% of low dose tPA as a bolus. Stroke severity, brain scans, and health outcomes were recorded for 214 patients treated at the Chia-Yi Christian Hospital in Taiwan. For patients of all stroke severity, the 15% bolus group had higher rates of good outcomes than in the 10% bolus group.
Interestingly, the 15% bolus dose was associated with a lower risk of poor outcomes for patients with severe and very severe strokes only. This was not the case for mild or moderate stroke patients. Given these findings, people with strokes of greater severity might require higher loading doses to restore blood flow to the affected brain region.
In this study, the researchers only administered “low dose” tPA, or 0.6 mg/kg. Similar studies have looked at stroke outcomes, but only with high doses of tPA (i.e. 0.9 mg/kg). Thus, the present findings help create a more robust literature surrounding tPA administration.
When stroke patients requiring tPA arrive to the hospital, physicians have the following question to consider: what dosage should be administered, and at what bolus dose?
Other work has associated higher doses with adverse outcomes, prompting the Taiwanese researchers to focus on the effectiveness of low dose tPA. Combined with the present findings, 0.6 mg/kg of tPA with a 15% bolus dose is likely the most effective combination. This information can help better inform physicians when making time-sensitive, life or death decisions.
Citations
Wong Y.S., Sung S.F., Wu C.S., Hsu Y.C., Su Y.H., Hung L.C., and Ong C.T. 2020. The impact of loading dose on outcome in stroke patients receiving low-dose tissue plasminogen activator thrombolytic therapy. Drug Design, Development and Therapy 14: 257-263.
Alex
"This title was very eye catching! That is so interesting that such a ..."
Alex
"This is really interesting! The fact that crops and plants are damaged is ..."
Alex
"Well done, this article is great and the information is very captivating! Ethics ..."
Alex
"I was intrigued throughout the whole article! This is such an interesting topic, ..."
Alex
"This is such an interesting article, and very relevant!! Great job at explaining ..."
Grandpa
"Honey You Did a good job I will forward to my eye doctor "
murphymv
"This article is fascinating because it delves into the details of the research ..."
murphymv
"I agree, adding the photo helped solidify the main finding. "
murphymv
"This is a fascinating finding. I hope this innovative approach to improving transplants ..."
Sherzilla
"This is a great article! I would really love to hear how exactly ..."
Sherzilla
"It's disappointment that these treatments were not very effective but hopefully other researchers ..."
Sherzilla
"I agree with your idea that we need to shift our focus to ..."
Sherzilla
"It's amazing to see how such an everyday household product such as ..."
Lauren Kageler
"I will be interested to see what the data looks like from the ..."
Lauren Kageler
"A very interesting article that emphasizes one of the many benefits that the ..."
maricha
"Great post! I had known about the plight of Little Browns, but I ..."
Sherzilla
"I assumed cancer patients were more at risk to the virus but I ..."
Sherzilla
"Great article! It sheds light on a topic that everyone is curious about. ..."
maricha
"This article is full of really important and relevant information! I really liked ..."
maricha
"Definitely a very newsworthy article! Nice job explaining the structure of the virus ..."
maricha
"It's interesting to think that humans aren't only species dealing with the global ..."
murphymv
"This is very interesting and well explained. I am not too familiar with ..."
Lauren Kageler
"Great article! This post is sure to be a useful resource for any ..."
Lauren Kageler
"Definitely seems like an odd pairing at first, but any step forward in ..."
murphymv
"What an interesting article! As you say, height and dementia seem unrelated at ..."
murphymv
"Great article! I learned several new methods of wildlife tracking. This seems like ..."
murphymv
"Very interesting topic! You explained cascade testing and its importance very well. I ..."
Alex
"This article is really interesting! What got me hooked right away was the ..."
Sabrina
"I found this article super interesting! It’s crazy how everyday products can cause ..."
Erin Heeschen
"I love the layout of this article; it's very eyecatching! The advancements of prosthetics ..."
murphymv
"Awesome article! I like the personality in the writing. Flash Graphene not only ..."
murphymv
"Very interesting work! I don't know a whole lot about genetics, but this ..."
Cami Meckley
"I think the idea of using virtual reality technology to better help prepare ..."
Erin Heeschen
"I wonder if there's a connection between tourist season and wildfires in the ..."
Ralph berezan
"Not bad Good work "
Michelle
"This sounds like it would be a great tool for medical students! ..."