SGLT2s like empagliflozin, dapagliflozin, ertugliflozin, and canagliflozin are getting more use in diabetes care as time goes on. As a geriatric pharmacist, I certainly recognize that these agents have a lot of potential benefits, but they can also have adverse outcomes. I wanted to touch briefly on two examples of the SGLT2s and the prescribing cascade.
First, recall the mechanism of action of the SGLT2 inhibitors as it will help you identify some of the potential adverse effects. These drugs lower glucose by increasing the elimination. Glucose is eliminated out through the urine. This excess glucose in the urine can contribute to two significant complications that could lead to the addition of new medications. The first complication is that excess glucose can be a fuel for various bugs to grow and replicate from. In addition, excess glucose in the urine will naturally try to pull water with it. This can lead to an increase in urine volume and an overall diuresis.
In a patient taking an SGLT2, one of the first things I’m monitoring for is genitourinary infections. Fungal infections, in particular, are a relatively common adverse effect. As you are monitoring patients over time, be sure to be aware of agents used to treat these infections. If you see frequent prescriptions for fluconazole or other agents used to treat yeast or other vaginal fungal infections, you should be reassessing the use of the SGLT2 inhibitor.
In addition to the use of antifungal agents, I also keep an eye out for frequent bacterial urinary tract infections. If you are seeing the need for antibiotic prophylaxis or frequent antibiotic use, you should ask yourself if the SGLT2 is contributing to this issue.
Urinary frequency is a significant problem for many elderly patients. It can lead to many patients reducing their fluid intake and cause non-adherence of necessary medications for blood pressure and heart failure (i.e. diuretics). Because SGLT2 inhibitors can contribute to this diuretic effect and ultimately urinary frequency, there is the potential for urinary anticholinergics to be added to manage this adverse effect. Whenever you see bladder anticholinergics added to a patient’s regimen for urinary frequency, you must look at the medication list as SGLT2 inhibitors could be a factor in worsening these symptoms.
I hope these examples of the SGLT2s and the prescribing cascade are helpful. Here are some more examples of the prescribing cascade that I’ve blogged about previously.