Sodium Chloride Supplements – Don’t Overlook Them
As you are reviewing a medication list, it can be easy to overlook supplements. The next time you review a medication list and you see sodium chloride supplements on the list, I want you to think of this post.
If you have a patient who needs more sodium, they likely have a problem maintaining a normal sodium level through their diet. There it is in case you needed your obvious fact of the day!!! However, the reason for hyponatremia could be due to multiple reasons (many medical), but as pharmacists, we must recognize that there are many drugs that can cause SIADH and ultimately lower serum sodium levels.
So when you see a patient on sodium chloride supplements, you should be reviewing if they are being treated with an SSRI, mirtazapine, MAOI, tricyclic, SNRI, etc. which have all been associated with SIADH.
I also look to ensure that the patient is not taking carbamazepine or oxcarbazepine (case study) for seizures, trigeminal neuralgia, bipolar disorder, or any other condition. These two drugs have are also well known to cause SIADH.
I virtually never see it used, but in this situation, I would look to see if they have diabetes and if they are taking chlorpropamide.
Tramadol has some SNRI type activity and was actually recently added to the Beers criteria for its potential to cause hyponatremia. This is another medication that I would check to see if my patient with hyponatremia was taking.
Assessing the use of diuretics is also important when we talk about electrolyte imbalances.
In addition, there are chemotherapy agents that can cause hyponatremia. If you know a patient had cancer or is actively being treated, this is something that should be further reviewed as a potential cause.
For the sake of completeness, let’s say you had a patient receiving oxcarbazepine and that this has been changed to a different medication. The hyponatremia has improved. Always remember to review those supplements as we can potentially get rid of the sodium supplement if the problem of the hyponatremia has been identified and fixed!