 Welcome back to our Med Smarter question of the week, where we're taking a smarter approach to preparing future physicians. Before we get started, if you'll take just a quick minute and click that like button and also subscribe and turn the bell on so that you'll be notified when we post new videos. As always, we begin with the last sentence before we read the rest of the vignette. Which of the following medications most likely would have elicited these symptoms? A 13 year old boy with a history of severe asthma presents to the emergency department in obvious respiratory distress. His parents reported using a rescue inhaler on the way to the emergency department with little improvement. After admission and multiple nebulizer treatments, he develops nausea, vomiting, and weakness. Studies reveal potassium levels of 2.5 milli equivalents per liter and U waves on the ECG. So which of the following medications most likely would have elicited these symptoms? Read the question again, take a look at the answer choices, come up with your answer and write it in the box below. So let's look at our most important things here. We have a patient with severe asthma already has this history. They used a rescue inhaler with little improvement and then at the ED they did nebulizer treatments. And the patient then developed nausea, vomiting, weakness, and our potassium level was low, that's important. And we had U waves on ECG. So the most important thing I want to look at here is the low potassium and the U waves. So which one of these medications could cause low potassium? Well, albuterol I know is a short acting beta agonist and it does have a side effect of potentially causing some low potassium. So I'm going to leave that one in. Myalutin is a leukotriene inhibitor and it does not have any problems with hypokalemia to my knowledge. So I'm going to go ahead and mark that one out. Theophelin, answer C, works more against cyclic AMP as a phosphodiesterase inhibitor so it doesn't have any effect on potassium either. So I'm going to mark that one out. Then epitropium, epitropium is an anti muscarinic and it has no problems associated with potassium. It does, however, do some nausea so there could be a little confusion there, but the potassium in U waves doesn't really cause us a problem here. So epitropium is not going to be one of my answer choices. So that leaves me with A, albuterol is my only possible answer here. And A is the correct answer. So what we're seeing here is a side effect of high doses of albuterol. Albuterol is a beta 2 agonist and it works mostly on the bronchioles as a bronchodilator by dilating that smooth muscle there. What it does here actually is it causes potassium to shift into the cells which leaves less potassium in the plasma to be able to function with the heart so we get hypokalemia. That hypokalemia not being able to function with the heart causes the ECG abnormalities because the cardiac cell membranes aren't stabilized. So those U waves are indicative of the hypokalemia secondary to the use of the short-acting beta agonists. If you found this material helpful for your studying, please like and consider subscribing to the channel. Also share this video so that more people can benefit from it like you have.