BETA - How are magnesium levels monitored?

So magnesium is one of the electrolytes that we all have and that it basically has a role in the cellular activity, right? Typically patients should have adequate levels of magnesium, which is also regulated by the kidneys as well, just to avoid problems. And the way that we have to monitor those is through blood tests, right? So it's very important for us to monitor those magnesium levels with just a basic metabolic panel or a comprehensive metabolic panel to make sure that the patient has no risk of either low magnesium or high magnesium, which could cause trouble afterwards. What would be some signs and symptoms that you may have high magnesium or low magnesium levels? They can share some symptoms for sure, but typically, for example, hypomagnesemia, so low magnesium, can present itself as muscle cramps, right? So sometimes our patients with myeloma do complain of occasional muscle cramps, and in occasions this low magnesium is the culprit of that. Fatigue, GI manifestations like diarrhea, nausea can happen in both scenarios, but in a more serious event, cardiac arrhythmias can happen. High magnesium can even cause cardiac death, right? So it should be extremely important for the patient to have adequate levels of magnesium, because some of our therapies can alter the magnesium levels typically to the lower end. But yeah, so those cardiac arrhythmias will be the ones that, the ones, manifestations that we have to monitor and be cautious about. How are low magnesium levels managed? So low levels of magnesium actually are very simply managed with supplementation, right? We can either do oral or IV supplementation, right? And based on how the patient is responding, we just need to adjust, right? Then typically when patients are being treated, these patients will have labs just before treatment, so we'll know at the time of the visits whether or not we need to make any adjustments. For the most part, it's not too hard to manage altogether. How are high levels of magnesium managed? Sometimes when a patient has high levels of magnesium, it's very likely that the patient is going to have other electrolytes than normalities and issues with the kidneys as well. Sometimes we might need to use the assistance of an nephrologist to help us make sure that the patient stays within acceptable ranges and out of trouble, right? Because if the patient has multiple electrolyte abnormalities, which sometimes can happen, even dialysis might be warranted at that point. So yeah, we just have to be cautious as to what type of situation we're dealing with. What treatments may affect magnesium levels? Most therapies in myeloma will affect electrolytes in general to some extent. The severity might vary for sure. The agents that might cause more alterations in magnesium might be chemotherapy-based, like cisplatinum. Cisplatinum can cause low magnesium for sure, and some proteasome inhibitors, like carfilzomib, can also cause low magnesium levels. So those are the patients that we would monitor more closely. For the cisplatin, we use less and less now, especially with the era of novel therapies. There is still a role for some patients to have chemotherapies and send certain instances. So whenever we have to use a cisplatin-based chemotherapy, we have to be mindful of that as well. And with carfilzomib, for instance, magnesium level is important not only because it can be tied to the medication itself, but also because carfilzomib can also have cardiac toxicities. So we have to be very cautious as to how we monitor these patients as well, just to make sure that they're safe. In reality, the problem typically is not the medication. It's not knowing what to do when the side effect appears. I try to tell the patients not to be afraid of the medications because of the side effects, but just to be aware of them so that we can know how to, number one, have some mitigation strategies, but number two, know how to manage them. What should patients know about over-the-counter magnesium supplementation? That's a little bit of a controversial topic for sure because typically, unless the patient really warrants a real supplementation, we have to be cautious with all the over-the-counter medications that we take. Some of them are not necessarily FDA regulated, so we don't truly know what is put in there for sure. I think multivitamins from credible brands are very acceptable for sure. We just have to make sure not to overdo it, and we have to always let our providers know what type of supplementation or natural, quote unquote, supplementation the patient is taking because it's important to have that communication. We never criticize the patient for taking X or Y supplement, but we just need to know. That's what it comes down to. As long as the patient is doing okay, just work with your provider and make sure that it doesn't have any negative impact on your outcome together.